3.5L rebuild?

[Bulldog]

Hi all,

Can anyone help me with this one? My 3.5L is overheating a lot. I've had the cooling system looked at which resulted in a recored radiator. I've added an electric fan in the front and cut some air vents in the back corners of the bonnet. Still gets hot and boils sometimes, especially when idling for a few mins after hard driving. My LR mech says he can look at engine probs (head gasket) but it's gonna cost $$$.

So, the question is this: do i save the cost of looking for problems and just pull the engine out and fix it/get it fixed, and replace other bits while i'm there? What's it going to cost for parts? What are the normal bits to change? It doesn't blow any smoke so do i leave the pistons/rings? I hear that the cam wears out. Will it cause probs if i put a non-std cam in?

Is the older 3.5 worth fixing or should i get a post-83 "stiff block" or is this only needed for a 3.9? Any ideas?

Thanks in advance...

[byron]

I'd be fist looking for a DEFINITIVE answer as to why it's overheating......and for a new mechanic!.....one who doesn't suggest a $4000 odd dollar engine rebuild!.......has the thermostat been checked?....is it new?....correct type?....is the viscous fan working CORRECTLY-tested?etc....tested for combustion gases in cooling system?.......an engine rebuild is your LAST resort - not your second attempt to fix overheating......the new radiator sounds like it may not have been needed [it didn't cure the overheating, did it?]

[byron]

Looking at your 1st paragraph again, I'd suggest you thoroughly check the viscous clutch in the fan - if they're ineffective they will cause exactly that.......and FIND A MECHANIC who can TEST stuff, rather than blindly replacing stuff like $600-$1000 radiators, then when that doesn't work want to do a $4000 engine rebuild!

Find a REPUTABLE Land Rover Specialist......ask for recommendations on here.......people know from experience who's good, fair and honest!

[Bulldog]

The fan isn't the viscous type (if thats the "run when needed type"). The thermostat was checked and ok (but the cooling guys were non-LR specialists). It's me thats thinking of the rebuild. The LR guys want to look at head gaskets etc. Can i check the operation of the water pump easily?

[byron]

The fan isn't the viscous type (if thats the "run when needed type"). The thermostat was checked and ok (but the cooling guys were non-LR specialists). It's me thats thinking of the rebuild. The LR guys want to look at head gaskets etc. Can i check the operation of the water pump easily?
If the water pump bearing is OK then pump OK.......check for combustion gases in reservoir tank with a "sniffer".....look for bubbles at least/rapid pressure build up!........Non -original LR thermostats can have too small a cross section for adequate flow.....is this solid fan BIG enough?.......why was the original removed......the original designers knew what they were doing when they specified one!!!........could the fan be too small/not move enough air fast enough.......have you ever heard the noise/amount of air moved by the original VC fans??????

[Bulldog]

Original VC fans? I thought the early RRs had a direct pulley fan? I'd be interested to know if this is true? It looks standard!?!

[Reads90]

mmmm ok
touching on some stuff byron has already said. Not having a Viscous fan could be your problem as i know far too many V8 who have taken off the viscous in the mayor belief that they will save 1 mpg and then find that they have mayor over heating problems.
My first step would be to replace the thermostate with a low temp one. (after all will not cost you more that about $20-30 ) and then see what happens.
As for head gasket, check for the usuall signs. Water in the oil. Oil in the water. Take the oil filler off while the engine is running and see if the engine is chuffing (ie smoking coming out of the oil filler hole like a steam train.)
It does depend on how the engine is over heating as i have know many people in the past that have had a blown head gasket on a V8 and ran around with it for weeks untill they can be asrsed to change it..

Finally there is a true frase for Land Rovers and that is, if it anit broke don't fix it.
Does the engine sound ruff as guts. Does it smoke really bad, does it use more oil than petrol. If the answers to this are no . Then why rebuild the engine.
If it is the head gasket then leave the engine in the car and change the gaskets. Simple easy job to and somthing you can do yourself.

[stikman]

I hear that the cam wears out. Will it cause probs if i put a non-std cam in?


I have had bad experiences with aftermarket cam in my 3.5. Mine had worn and the mechanic replaced it with a stage 1 something (will look it up if you need to find out) instead of a genuine part. I have since changed mechanics (old one was also supposed to be a LR expert also) and now use Ricks on the Gold Coast. He puts a lot of my current lack of torque and low engine vacume down to the cam. Luckily he said this was one of the better aftermarket cams he has seen in the 3.5 as most of them he cannot even get to idle properly :eek: . After my Cam was replaced and the car was not running well the mechanic sent me to Ricks to get them to tune it. It has been going to Ricks ever since. Rick suggests the genuine 3.9 cam in the 3.5 when doing the job.
In saying that i know a few people on this forum with aftermarket cams in their rover engines and are not unhappy with the results.

[byron]

Original VC fans? I thought the early RRs had a direct pulley fan? I'd be interested to know if this is true? It looks standard!?!

OOPs sorry......I did have early RR's but not that early......they got rid of the solid 5 bladed fan about 1975 and went to a VC 7 bladed, then 11 bladed VC fan.......why not try fitting a VC fan?......it sure sounds as if the thing can't cool it enough.....is there a shroud fitted?........how big is the electric fan you fitted????......a bad VC fan and fully working dual auxilliary fans on later models STILL result in overheating like you've described.! [after a hard drive and then just idling]

[Reads90]

Also when was it turned last this will cause it to over heat too.

But anyway replacing the head gasket is not a difficult job to do your self and chaep to do
Now the link to my faveroute site since moving to Aus:D

Head Gasket Set
Part Number : STC1566
Notes : 3.5 Carb
Head Gasket Set
Price : £ 14.50
http://www.land-rover-parts-shop.com/shop/en/browse/Range+Rover+Classic/1/0/9/29/44/100540

will post at a cost of about $15 and can pay by paypal

[ladas]

Pop it into Glen @ Roverland in Boronia/Ferntree Gully..............

He should know what is needed.

[byron]

Also when was it turned last this will cause it to over heat too.

But anyway replacing the head gasket is not a difficult job to do your self and chaep to do
Now the link to my faveroute site since moving to Aus:D

Head Gasket Set
Part Number : STC1566
Notes : 3.5 Carb
Head Gasket Set
Price : £ 14.50
http://www.land-rover-parts-shop.com/shop/en/browse/Range+Rover+Classic/1/0/9/29/44/100540

will post at a cost of about $15 and can pay by paypal

Brilliant prices!!!!!!

But unless you have so much time on your hands that you do Head Gaskets and Head Jobs for passing the time, I'd TEST for a leaking gasket first- soooooo easy!

[Bulldog]

Yes there is a shroud fitted. The electric fan is 10-12 inches (yes it blowing in the right direction!!!) fitted to the front of the radiator. How does the VC fan work better than the one i've got? I thought the olny difference was that it stops sometimes... or is it the number of blades that does the trick?

Service quite regular for a short-trip-every-few-weeks kind of car...

[Reads90]

a couple of question for you
How long have you had this truck
How long has it been over heating

[Reads90]

Brilliant prices!!!!!!

But unless you have so much time on your hands that you do Head Gaskets and Head Jobs for passing the time, I'd TEST for a leaking gasket first- soooooo easy!


Oh yeah agreed but at least if you do need to do it , its not the end of the world

[byron]

Yes there is a shroud fitted. The electric fan is 10-12 inches (yes it blowing in the right direction!!!) fitted to the front of the radiator. How does the VC fan work better than the one i've got? I thought the olny difference was that it stops sometimes... or is it the number of blades that does the trick?

Service quite regular for a short-trip-every-few-weeks kind of car...

the newest fans [16 blades?] shift ENORMOUS amounts of air......and their drive motor isn't a 12volt one......it's a V8 3.5 - 4.6 litres!!!!......much more power to move the air through in BIG volumes!!!!

I'd go to an LR expert though, heaps cheaper than spending lots of dollars on new parts to throw at it!........FIND the problem, then fix the problem! - Simple!

[Reads90]

Yes there is a shroud fitted. The electric fan is 10-12 inches (yes it blowing in the right direction!!!) fitted to the front of the radiator. How does the VC fan work better than the one i've got? I thought the olny difference was that it stops sometimes... or is it the number of blades that does the trick?

Service quite regular for a short-trip-every-few-weeks kind of car...


it is proved a fan pulling air though the rad works a hell of a lot better than a fan pushing air though the rad

[Bulldog]

Had it 3 years. Overheating since i got it, but it was missing the carby linkage for a while... Radiator was done about 2 years ago.

[Reads90]

the newest fans [16 blades?] shift ENORMOUS amounts of air......and their drive motor isn't a 12volt one......it's a V8 3.5 - 4.6 litres!!!!......much more power to move the air through in BIG volumes!!!!

- Simple!


:D :D :D :D

[Reads90]

Had it 3 years. Overheating since i got it, but it was missing the carby linkage for a while... Radiator was done about 2 years ago.


well if it was the gasket then you would have had more serious problems by now.
Looking more and more like the (sorry) crapy fan on the front :)
Get it off and get a real one on.

The other problem with the fans on the front , is that they don't have any funnel system and only push air thought the rad that wants to go. Where as a fan on the other side would be in a couling and therefore force air in though the rad and therefore working about 10 times better

[Bulldog]

Added the electric fan myself after overheating probs and after recored radiator...

[Reads90]

Added the electric fan myself after overheating probs and after recored radiator...


So what did it have before that then

[Bulldog]

Fan belt driven fan in engine bay. Still there. Electric fan is extra in front of rad...

[Reads90]

Fan belt driven fan in engine bay. Still there. Electric fan is extra in front of rad...

AHH ok so you have still got a fan in couling and a fan on the front of the rad.

mmmm how big is the fan on the front whoopps ok already said 10-12 inches. mmmmmm not very big fan do you have one or two
How does it work . ie is it on all the time or what

[Reads90]

How close is the fan to the rad.

[Bulldog]

Switched manually from dash - i've always got my eye on the temp guage and i switch it in before it gets too warm. Didn't want to add too much stuff to block up the front of the radiator...

[muddydigger]

Rangies are natorious for over heating. If the radiator was done 2 years ago you would almost be able to eliminate it from the causes ( unless you just use water in which case it could be scale build up).
If its fan is original then i would leave it alone, its done scince it was built .

Some things I would be looking at would timming if its to far retarded it will over heat.
fuel mixtures.
oil levels.
thermostat check it opens at the right time from memory its 89 degrees.
I wouldnt think head gaskets it would be having more serious probs by now.
does it actually use water?
In car heating system.
check for leaks
check to ensure the cap pressurises the system (rover engines need to presurized to stop premature boiling).
When it boils if you switch the heater n will the temp come down?
Electric fans are far more efficiant to drag air through the radiator not push.
The fan blades of the thermo fan may need to turned over, symply reversing polarity wont ensure maximum flow from them.

[Reads90]

Switched manually from dash - i've always got my eye on the temp guage and i switch it in before it gets too warm. Didn't want to add too much stuff to block up the front of the radiator...

To work the fan should be almost touching the rad. Any gap will make it not work very well

[Bulldog]

The electric fan is almost touching the rad (3mm). Heater makes little difference to temp when hot. Water is almost always full, maybe down 1/2 a litre sometimes - except when it boils and looses a few litres...

[Reads90]

mmmmmmmmmmm

Ok then i would drain the water and replace the thermostate with a low temp one. You can get a normal which is 88 degrees but you can get a 79/ 80 ish degree one. Then rep-lace the water and coolant and try again. will not cost alot but will sort that out and moved on to the next if that does not work.
And get it tuned as the same time. As said before if it is out of timing that will cause it to over heat.

[Bulldog]

Thanks. I'll try that... What about radiator hoses? Change them? I've heard a small crack/hole can cause overheating...

[muddydigger]

check timming and fuel mixtures.
Drain water from radiator and fill it anti carossin anti boil.
Ensure car is on a good hill to refill so the rear bumper is lower then the top of the radator so it doesnt get airlocks and swich on the heater to as well.

[Reads90]

Thanks. I'll try that... What about radiator hoses? Change them? I've heard a small crack/hole can cause overheating...


why are they leaking . If not then why :)

[Bulldog]

The other problem with the fans on the front , is that they don't have any funnel system and only push air thought the rad that wants to go. Where as a fan on the other side would be in a couling and therefore force air in though the rad and therefore working about 10 times better

Could the elec fan be doing more harm than good (blocking the airflow).

[Reads90]

Could the elec fan be doing more harm than good (blocking the airflow).

in my mind yeah . take it off check the rad is not blocked . Ie you can see light thoughn it.

[muddydigger]

Could the elec fan be doing more harm than good (blocking the airflow).

No it wont do anything to it. Every car with aircon has the thermo fan on the front so it shouldnt make anydiffrence at all.

[PhilipA]

You know there is an obscure but simple reason that old carby Rangies overheatthet is often overlooked.
The water vent from the inlet manifold, which is the highest point in the system, gets blocked and an airlock results.
Follow the hose which goes from the RH radiator tank to the middle of the manifold and check that the little steel pipe stub is clear. If not , get a drill and drill it clear with the drill in a pair of pliers. Do not use a drill unless you are really good as there is a water jacket there which is quite narrow.
A viscous fan has a fluid coupling like a torque converter. This enables the fan to be of a larger capacity than a straight steel fan, as the speed is governed by the slip in the clutch, to about 3K RPM.In addition they usually have a bimetallic strip , which closes an oil gallery and stiffens it up when hot.
Old Rangies also can get hot if the head gaskets are leaking into the valley. There can be no water loss, yet there could be large leaks. In this case the engine will be blowing oil out of the valley seals near the distributor. When I pulled my 3.5 down, I even found a burnt "gulley" in the head where the gasses had pushed through. The outside "short" headbolts cause this and should be deleted on fitting new gaskets , or only done up to say 20Ft/Lb.
Regards Philip A

[Bulldog]

You know there is an obscure but simple reason that old carby Rangies overheatthet is often overlooked.
The water vent from the inlet manifold, which is the highest point in the system, gets blocked and an airlock results.
Follow the hose which goes from the RH radiator tank to the middle of the manifold and check that the little steel pipe stub is clear. If not , get a drill and drill it clear with the drill in a pair of pliers. Do not use a drill unless you are really good as there is a water jacket there which is quite narrow.
A viscous fan has a fluid coupling like a torque converter. This enables the fan to be of a larger capacity than a straight steel fan, as the speed is governed by the slip in the clutch, to about 3K RPM.In addition they usually have a bimetallic strip , which closes an oil gallery and stiffens it up when hot.
Old Rangies also can get hot if the head gaskets are leaking into the valley. There can be no water loss, yet there could be large leaks. In this case the engine will be blowing oil out of the valley seals near the distributor. When I pulled my 3.5 down, I even found a burnt "gulley" in the head where the gasses had pushed through. The outside "short" headbolts cause this and should be deleted on fitting new gaskets , or only done up to say 20Ft/Lb.
Regards Philip A

Thanks for the ideas. The 4 bolts are out (i've heard of this before). Is it a big job to replace my fan with the viscous type? Do they bolt straight on?

[justinc]

I would actually remove the water pump and check the impeller and the condition of the face behind the impeller for serious pitting etc. The impeller blades actually had broken on one of my 3.5's, causing BIG overheating problems, so much so that I thought it had done a head gasket at first.
It'll cost you about an hour or so with an early rangie engine, and about $6 for a gasket.

Also, if you are running SU's still, get some one who knows about them to balance and set the mixtures, and possibly even fit richer profile needles, that way you can run more spark advance without detonation, and it should run cooler under load too.

After market cams aren't always the problem, it is the way they are fitted/ timed that can cause a problem. If they aren't dialled in correctly then a good cam profile will become useless, causing poor vacuum and torque etc.
I have had good results with Dynotec PC216 and the higher lift PC217 cams, and you must use decent lifters with them, NOT holden ones.

Furthemore, I had rangies over in the west, and I clearly remember driving for long distances with a full load in my old '81 and on a day that was reaching at least 50 degrees I had no cooling issues. Infact the only overheating problems I have ever had was with a blown head gasket, and with that broken water pump I mentioned. As the engine is ally, it will cool very efficiently anyway, and the Rad is well big enough for a small engine like this. I don't think they are renowned for inherent overheating really at all, except maybe in the UAE or Saudi Arabia etc.

JC

[muddydigger]

Thanks for the ideas. The 4 bolts are out (i've heard of this before). Is it a big job to replace my fan with the viscous type? Do they bolt straight on?

Personaly if you worried Id be removing the fan on it and putting twin 14 inch thermo fans on. I did this to mine and mounted them on a alluminum shroud i made up.
It will enable the car to get to operating temp quicker, use less fuel as it not continually turning a fan andd run quieter too. its also a lot more reliable.
I neve had a problume over heating even when doing some pretty hard stiff on 38 degree days with the aircon on. just my 2c worth.

[Bulldog]

Personaly if you worried Id be removing the fan on it and putting twin 14 inch thermo fans on. I did this to mine and mounted them on a alluminum shroud i made up.
It will enable the car to get to operating temp quicker, use less fuel as it not continually turning a fan andd run quieter too. its also a lot more reliable.
I neve had a problume over heating even when doing some pretty hard stiff on 38 degree days with the aircon on. just my 2c worth.

Do you mean remove the original belt driven fan? Are they wired-on or swithched by something?

[muddydigger]

Do you mean remove the original belt driven fan? Are they wired-on or swithched by something?

Yes remove the engine driven fan altogther. this will enable th room to fit the twin 14 inches.( twin 16s wont fit I tryed twin 14s are as big as you can fit)> If you think about it the normal viscos fan is 16 inch so twin 14 will generate alot more air. they are thermasticallycontroled with a probe in he top radiator hose. If you can buy a complete kit which has the temp controle in it. this will enble you to set the temp at which the thermos will cut in. if its all setup right the fans will run for about 15 to 25 seconds in normal driving conditions and then swith off. they shouldnt need to come on at all whilst your moving at say 60 klmh. Davies craig does a whole kit. You should be able to but all the stuff fom any reputable car store even Repco.
Alternativly ive heard of Ford Falcon ef thermos being used as well but youll still need to buy the thermo temp switch.

[Bulldog]

Wow! Very interesting... i'll look into that.

[Bulldog]

Thanks again for all your help guys. Much appriciated. Lots of things for me to try...

[dungarover]

Regards to aftermrket cams, it's all bull****. I've always used Dyntech cams (std profile) and never had any issues. Like JustinC said, if they're badly timed and fitted this may cause a few issues. I pulled mine out 3 times before I was happy with the cam timing (bit anal but it was worth it).

Ivan tighe cams are also not bad, fitted one to my 93 Rangie and it had 70,000 kms on it before I sold the engine (shouldn't have but needed the money when the insurance company ****ed me up the **** :eek: :eek: :eek: :mad: :mad: :mad: :mad: ).

Trav

[Bulldog]

There's a Wade cam on ebay for a Rover V8. I was thinking about this. Maybe saving it for the future if/when i need/want it...

[Mark86]

I agree with the aftermarket cams i had a torquemaster cam put in when i rebuilt 3.5 to 4.0 and i think its great bit more lumpy idle but it works great.
Yeah check the inlet pipe on the carby manifold as my old p6v8 3.5 with su's
got clogged up over time and check what fan your rangie should have even my 1974 p6 v8 has a viscous fan 7 blade.

All the best Mark

[walker]

You definately want the twin AU Falcom thermo fans. They are a very easy to fit and work well. I got my fans off Ebay including the shroud for about $170. You defintaly want to use the plastic shroud or make up your own as this makes a heap of diiference.
You will find that the nose on the water pump which held the old fan blades might be in the way of the thermo's. With a bit of help I was able to make my own lathe and cut off the nose. All I did was but a socket in an electric drill wheck fitted the bolt on the end of the nose. With this I could spin it around then I held a hacksaw in place and it cut it off an still kept it all balanced.:D

I used crow cams in mine. I also made sure I got the "towing cam" which gives you a bit more torque down low.

[djam1]

I hope this helps I think you should look seriously at what has been said by the brothers in terms of why it’s overheating.
As a side comment I personally am suspicious of the idea of running a 4x4 in deep sand in 45c heat with an electric fan I think that it will probably end in tears. (A great idea in the UK but not here)
I am however positive about the rover v8 in hot conditions with the experience that I have had in the past. These things with the right radiator will handle the heat as well as any other motor.
Don’t use a standard radiator use something that is a little more efficient than that, I know a guy in Alice Springs that has advised Rover on how they should design their radiators (mind you they didn’t listen) I can put you in touch with him if you like, I have towed a 30 odd foot caravan in heat over 50c without issue all with a 3.5 litre Range Rover with a radiator that he designed.
I had to replace the 3.5 litre Rover motor in my Stage 1 Last week and I ended up buying a long motor from Les Richmond Automotive in Melbourne for $2500 I ended up with a stiff block high compression motor that thus far I am more than happy with. Speak to Andrew I have found him more than competent and I am impressed with the quality of their product.
Duane

[jasper110]

incidentally, how do you test to see if the viscous fan is working correctly?

[byron]

incidentally, how do you test to see if the viscous fan is working correctly?

There are tests that use a Tachometer for the engine, a strobe light and a Hand held Tachometer for the fanand compare against the manufacturers specs......but if it spins easily by hand - it's f###ed....

.....it should turn with resistance when cold and then when hot should be harder to turn.

[Blknight.aus]

warm up the center metal bit with a hot air gun and it should offer more resistance when turned by hand by the blade against its normal rotation direction.

[Graeme]

I would actually remove the water pump and check the impeller and the condition of the face behind the impeller for serious pitting etc. The impeller blades actually had broken on one of my 3.5's, causing BIG overheating problems, so much so that I thought it had done a head gasket at first.
It'll cost you about an hour or so with an early rangie engine, and about $6 for a gasket.

<snip>
JC

When I bought my 76 RR many years ago, the water pump had just been replaced and the old one was with the vehicle. The housing behind the impellor was very badly corroded. I don't know what symptoms led to its replacement, but I suspect it wouldn't pump enough on idle.

[Debacle]

incidentally, how do you test to see if the viscous fan is working correctly?

Roll up some newspaper, rev motor and poke the end into the blades (do it very gently, dont just jam it in). If it shreds the newspaper it is fine. If the fan stops then it is stuffed.

[byron]

Roll up some newspaper, rev motor and poke the end into the blades (do it very gently, dont just jam it in). If it shreds the newspaper it is fine. If the fan stops then it is stuffed.



That's a really good idea for testing the amount of "drive" in the VC clutch........of course you have to do it carefully.........another test, but more risky if the clutch is good, is do what an NRMA guy did once on a g/f's Volvo, hold the fan then start engine - if you can hold it then it's had it.......I think he could feel it spinned too easily when spun by hand at first!

[PhilipA]

In a really stuffed one it will continue turning after you spin it.
A good one will stop immediately.
I could see the one on my son's BMW was stuffed when he turned off the engine and the fan kept spinning.
A good Range Rover viscous will ROAR for about 1 minute after start up as the fluid pools in the bottom overnight.
It should be just a bit firm to turn, eg you should be able to turn with your little pinkie but with a bit of effort.
Regards Philip A