Thread: 3.9L V8 on heat - is this normal?

Philip,

Like I said, I hope it's not too difficult to follow without photos. The car is currently getting sorted out at the mechanic's. As soon as I get it back, I will take photos and post details. As for feeding you information bit by bit, I'm pretty new to the rover engine, and am not sure what the "normal" setup should be.

The engine that's in the car came out of a rolled Rangie, it's coupled to a 5 speed manual gearbox, which I'm told is not out of the rangie... It's got a plentitude of additional sensors and wires on the loom that are not in use (oil temp sender, additional "thermocouple" which seems to be in the cooling system - thermoswitch for a thermofan??)...

...The point I'm trying to stress here is that I don't know what's supposed to go where, let alone how THIS engine's been put together...

... what I can tell you is that it has power to spare! If you bear with me, I will post details when I get the car back.

Cheers
Bojan

BTW, as for feeding you peacemeal information, I'm only posting information after I find out / read about it / have it explained to me. I knew a lot less about the engine a week ago than I do now... and even now I know very little!! So apologies to all that find it frustrating.

Look, it would help if you can tell.
1 What sort of car is the 3.9 in?
2 What model are all the bits from? eg radiator, inlet manifold,overflow tank? The 3.9 Range Rover radiator has 2 small nipples for hoses on the RH radiator tank. Does the one in the car?
3 What is the layout of hoses? Thus my request for photos.
The 3.9 in a Range Rover and disco has 2 heater pipes which run along the top of the right hand rocker cover, and these were added to provide a fill point at the highest point of the engine and heater and stop air pockets. Does your engine have this?
The 3.9 has plastic header/expansion tank with a large pipe to the bottom hose. Does your engine have this?.

I would dissuade a mechanic from adlibbing on adding hoses etc unless you are very sure he knows what he is doing, as Land Rover cooling design is very good and designed for the most extreme conditions.

Also Rover V8s HATE being overheated and it is possible for the sleeves to become loose after even one overheat. In this case the head gaskets need not have been blown.
Regards Philip A

Phillip,

1. The engine now resides in a Defender 90. The guy that owned it before me did all the engine transplant work.
2. Engine is out of a '91 Rangie (to the best of my knowledge).
The radiator could be from the 200Tdi that was originally fitted, but I simply I don't know. It's defiantely not out of the rangie. It fits perfectly in the defender (all the right mounts) has an inlet valve at the top right hand corner (looking from the front of the car into the engine bay), outlet at the bottom left hand corner, small hose connection at the top left hand corner (going to the header tank), large bleed / fill screw in the top left hand corner (above the smoll hose connection).

The expansion tank is plastic, and has one largish (10-12mm diameter?) and one smallish (5 - 6mm dialeter) connection. Has a 15 PSI pressure release cap on top. Originally (when I bought it) only the smaller pipe was connected to the cooling circuit (to the LH top of the radiator). The larger diameter pipe was blocked off (a small tube with a bolt on the other end).
The header tank was effectively used as an expansion tank.

The heater is no longer connected to the cooling circuit. There are two connections where I think the heater was connected (one off the pump, and one off the block, near the top end of the V, from memory), but these have been short-circuited by a small S-bend tube.

3.) I think photos are a great idea re: layout of hoses - I have trouble following what I just wrote... and I just wrote it!!!

With regard to your other suggestions:

"I would dissuade a mechanic from adlibbing on adding hoses etc unless you are very sure he knows what he is doing, as Land Rover cooling design is very good and designed for the most extreme conditions."

Hmm... I would be tempted to say he does know what he's doing (he's a Land Rover mechanic, and has been for the past 20 years, does nothing but rovers)... but then again, he did leave a massive airlock in the radiator... so I really don't know. I think it was done by one of his staff, and he'll be looking at it this time.

"Also Rover V8s HATE being overheated and it is possible for the sleeves to become loose after even one overheat. In this case the head gaskets need not have been blown.
Regards Philip A"

Philip, this is my major concern at this stage.

I've spoken to several mechanics, some with LR specific knowledge, and some with general knowledge. The general concensus (with one exception) seems to be that if it hadn't blown the head gasket, it will most likely be OK.

What are your thoughts?

Is there any way to tell, and if not, is there anything I could / should do over the next month or so to make the problem evident?

At this stage I have something to go back to the mechanic on. If it is / becomes evident in the next couple of months, it would be reasonable to assert that it was directly related to the engine overheating.

Anything over that, and I'm afraid I'm on my own. (Mild panic setting in with even a slightest thought of a $7k engine rebuild.)

OK,
That clears a few issues.
I am not an expert on Defenders, but AFAIK a Defender Rad should have an intercooler at one end,so is narrower than a V8 Rad. No intercooler would suggest it is 110V8 rad.
The layout sounds OK, but a 3.9 usually has a 13mm or so ID pipe from the lower hose to the expansion bottle.

This is not necessary however (as 3.5s never had them) and it should cool fine with just the hoses there.
I think the problem has been caused simply by the mechanic not filling it properly, however when it is a "custom" installation its hard to blame anyone.

With regards to a sleeve shifting, the way to tell
is usually a tapping noise when warm, which is the sleeve moving up and down and hitting the head, as the fire ring of the gasket is outside the OD of the sleeve and there is 20thou or so space.
Also the engine will mysteriously lose water without any in the oil.
I would be asking the mechanic to sign a letter guaranteeing to fix a moved sleeve if it happens in the next 12 months.
regards Philip A

Originally Posted by PhilipA

OK,
I would be asking the mechanic to sign a letter guaranteeing to fix a moved sleeve if it happens in the next 12 months.
regards Philip A

I can't imagine anyone would sign said letter, unless the customer was paying for the repair.

Well I presented a letter to the guy who shall remain nameless who left only 100MM of oil in my BW transfer case after removing the transmission for a rear main seal.
He was willing to stand by his error if it failed within say 12 months, but at least it should be in writing setting out the situation and the demand, so that there is no confusion or miscommunication in the future.
Regards Philip A

All I am saying is that there is no way on Gods green Earth that I would guarantee the longevity of an engine with unknown mileage, in a converted vehicle, with suspect cooling system for any longer than the standard 1/2 warranty. Once it is out of the yard, too bad...

Sounds like a V8 defender radiator to me, as no intercooler on the side.

As for the mechanic signing a slipped sleeve guarantee for 12 months it seems like an awful good idea to me , but as BigJon said, the mechanic may not see it as reasonable. Having said that, if the sleeve slipped in the next couple of months, I would be expecting him to fix it, as the engine overheating is a direct consequence of negligence on his behalf.

Really, if I think about it, if the overheating has weakened the block, and the sleeve slips as a result even after two months (provided the engine hasn't been overheated again), it was a result of the negligent action so I don't think it would be unreasonable.

I'm an engineer, and If I design a bridge, a building foundation ... or anything else for that matter, my work has to stand up to scrutiny for the design life of the product. If I'm found to be negligent 20 years down the track, I and the company I worked for might be sued for damages. That's why PI insurance is running sky high.

My next question then is, what is a reasonable period of time in which one might expect the damage from overheatig to become evident. Conversely, what are the chances of getting a slipped sleeve without overheating the engine?



Any thoughts?