300Tdi Random overheat

[TonyC]

Hi All,

I have a 300Tdi 130.
The radiator has been rodded in the last 18 months, the baffle hole reduced and a VDO mechanical temp gauge and low coolant alarm fitted.

Coming home from Wagga on Sunday, with air temp in the low to mid 30s we stopped for a few photos and left the car running with the air con on. When we got back in the temp was 115 Deg:eek:.
Air off, heater on and gently got some road speed got the temp slowly back to 100. At the next town I stopped and pored water over the thermostat housing, this dropped the temp right back to the stop on the gauge (40) restarted the car and the temp came back up to 85 at a reasonable rate.
Headed off, air con on, 100 km/h temp fluctuating between 88-95 like it always does under these conditions. All good for 65 km the the temp starts to rise again, stop repeat and all is good for the last 80 km home. On the second stop I cracked both the thermostat and radiator bungs and got no air just coolant.

The trip up to Wagga on Friday was without incident and outside air temps up to 44 deg.

I had this happen about a year ago following a thermostat change (it was sticking open) and changed the thermostat again and that seemed to fix the problem.

So do I have
1) A second sticking closed thermostat (both bought at the same time).
2) A randomly failing fan clutch.
3) Something floating around in my cooling system randomly blocking stuff.

Thanks in advance

Tony

[Blknight.aus]

sounds like the fans on the way out or its time to pulland test the themostat.

[PAT303]

Fan. Pat

[TonyC]

Thanks for that,
I think I'll order 1 of each, As much as I'd like to know which is the culprit, I want it fixed more.

BTW
Does a 300Tdi need a fan at hi way speeds? I had a Suzuki Sierra that I had removed the engine fan and fitted an electric and it only ever came on in hot stationary traffic or hard slow 4WDing.
And no, I'm not thinking of removing the fan from the LR.

Thanks again

Tony

[TonyC]

Hi All,
An update on this.
I replaced the thermostat, and the temperature variations on the mechanical VDO gauge seem smother than with the old thermostat.
I have not had another over heat.

Tony

[DiscoMick]

Sounds good.

I notice on my 300Tdi the electric fans come on with the air-con and stop when its turned off. Is yours the same?

Is anything blocking your airflow, such as driving lights?

[TonyC]

Sounds good.

I notice on my 300Tdi the electric fans come on with the air-con and stop when its turned off. Is yours the same?

Is anything blocking your airflow, such as driving lights?

Hi Mick?
Yes that is normal for the electric fan.
I do have driving lights and a front bar, but this is more random than that. As per my original post, it was fine in the mid forties on the way up to Wagga but did the overheat trick twice in the way home in mid thirties.

The radiator is good, water pump is near new.
when it first did it, two thermostats ago it did it to me in mid twenties, but other days in high temps it was OK.

I'm hopping the two thermostats I got at the same time were the same batch both with a fault, I guess time will tell.

Tony

[lokka]

When you first start it from cold dose the fan spin at full speed then slow down after about 30-60 secs ?

If not i would be looking at the fan clutch as they spin at full speed until the oil in them spreads after running for a short time .

Im not sure if they are the same as the rangie type as a ford clutch hub fits and is only about 30 bucks compaired to 100+ for the LR unit

[TonyC]

Hi Lokka,

I had not heard the locked up from the start, I'll try it.

What Ford fan fits?

I don't think it's the fan, as it doesn't get hot under load, over the school holidays it did a few hard low second climbs and and the temp didn't get over 92, but the weather was cool.

It might be next summer till I know for sure.

Tony

[lokka]

Have a look here EA,EB by the looks will work good tec in this thread

http://www.aulro.com/afvb/projects-tutorials/61474-300tdi-viscous-fan-bearing-solutions.html

[rainman]

I hope no one minds resurrecting an old-ish thread. I'm having even more randomness with my 300Tdi 130.

The week end before last, 6:00am after about 5 or 10 minutes of driving on 70~80 km/h roads with ambient air temperature about 8 degrees my (6 month old) mechanical VDO gauge was climbing slowly to the mid 80 degree mark as normal when it just skyrocketed. Within about 15 seconds it was at 120 degrees. I pulled over and it had dumped "a lot" of coolant out of the expansion tank cap. I figured my thermostat was stuck shut. I had no water with me and a lot of hills between where I was and home so I called for a tow truck.

I replaced the thermostat, topped up and bled the system, drove it, checked it, and drove it on a couple of short trips; all seemed fine.

Last week end I left home heading up the coast. Again, 5 minutes into the drive at 70~80 km/h with no hills the temperature shot up to about 115 degrees. I pulled over and just as I did it started dropping almost as quickly as it rose. I checked for coolant loss, none, removed the cap on the expansion tank; it was very warm but not boiling. I put it down to an air lock in the system so once it had settled at about 92 I kept going and it sat on 94 to 95 for the next hour on the highway at 100km/h. It then spent most of the rest of the afternoon crawling up and down a muddy hill in low 1st at 90 to 91 degrees. Next morning the air temperature was about 10 degrees. I drove back home down the highway at 100km/h sitting on 91 degrees.

Yesterday saw about 70 km around town with the temp in the low 90s. Last night, 5 minute drive to the shops, fine. Coming home, again it shot right off the gauge. Made it home and again it had dumped coolant and was boiling in the tank.

This is a bit of a novel, sorry, but it has me stumped. I can't see it being the fan because it always happens at moderate speeds and didn't happen at low speed. I have a new water pump to go on, but I can't see how the water pump can decide when to and when not to work.

James.

[wrinklearthur]

Hi James

There has been quite a lot of us with 300 TDi's, that have experienced what you are going through at the moment.

I changed all sorts of things like the water pump, thermostat, --- etc. It wasn't until I replaced the radiator that all the overheating problems disappeared

I am not a chemist but old stale coolant looks to be the culprit, this in turn leaves a residue called plaque inside the radiator core tubes, some of the 300 TDi engines have had their coolant left too long without being flushed out and replaced with new.
Rodding out the core is maybe not enough to remove this build up and overheating problems can keep on occurring even after this has been done.

I replaced my radiator with a new aftermarket copper-cored radiator, the over heating has not occurred since doing this twelve months ago and I have not been easy on that engine when doing work such as towing heavy loads on a car trailer in hilly country.
.

[rainman]

Thanks Arthur. I feared as much. My radiator is a bit of an unknown. I've had the vehicle for 4 years, the first 3 of which it was under an almost complete restoration so it did sit a fair bit, but was started and plodded around from time to time. The radiator does look "newish" so I suspect it was replaced or "worked on" not long before I bought the car, but again, it did sit around for 3 years.

Perhaps for now I will replace the water pump and just not go too far from home.

Thanks again,
James

[TonyC]

Hi,
Whilst I don't disagree with Arthur re the slow loss of radiator efficiency, I would have thought that would show as ambient temp dependent, IE hot weather high load = overheat. And that failing fan would show as high load low speed = overheat.

Nether pattern showed with mine.

I have been thinking about getting an infrared thermometer so if/when mine does it again I can get temps in and out of the radiator, the block and heater hose outlet.

All the best with yours James.

Tony

[chazza]

Before you buy a new pump James, buy a thermometer as Tony suggests. You can use it to check the temperature of the radiator in various places e.g. if it is warmer at the bottom than across the top, it indicates that the core is blocked down there. Similarly you can check the temperature of the coolant at the top and bottom hose to see what difference there is.

I don't think old coolant is necessarily the problem, I rarely change mine; but using hard-water in the system will cause blockages,

Cheers Charlie

[rainman]

I already had the water pump Charlie, so I fitted it Tuesday night. As suspected, there was nothing wrong with the old pump so I'll keep it as a spare.

And, of course this made no difference - 10 minutes into a drive yesterday at about the point where the thermostat opens the temperature sky rocketed. I pulled over and let of cool down for 15 minutes, then kept going and it ran at 91 -94 degrees for the rest of the afternoon.

I think I'm just going to have it looked at. I don't really have the time to keep playing around with it myself. I'll keep everyone posted with the outcome.

Thanks everyone ;)
James

[Diff]

After 5 years over overheating problems while towing or under load I think it has finally been fixed with a new radiator. I had tried two water pumps, three thermostats, viscus hub, new thermo fans and roded the old radiator. There were also multiple coolant changes. So from all of this I believe that the 300tdi radiators get blocked and should be replaced when problems start.

[Spel1]

Agree with Arthur and Diff. Radiator is most likely the problem. A nice new good quality core will have you running mid 80's even under load. I got a new core recently, was only going to get the old one rodded but it was coming apart at the seams literally from the system being pressurised for a while by a bad head and gasket, but it looked ok while it was in, only being a few years old. With the new core now only just gets to 90 pushing hard up long hills runs mid 80's around town even pulling a trailer load of concrete and dirt.

[lokka]

The standard fitment rads in the tdi defender and discos are crap the end tank that has the outlet/inlet has a baffle to make the rad a dual pass tho through some bright idea in the design of the rad the twits put a bloody hole about 5/8 through the baffle which causes the water to take the path of least resistance which is in and out either end of the bloody tank without passing through the rad core .
This is why the rads allways block up due to lack of flow and then the motor will run hot and over heat and all manner of manure hits the fan and gets flung about .
I had this shown to me by the bloke at burtons radiators he offered to recore and fit a proper baffle that divided the end tank and made the rad a true dual pass tho i did not like the $400+ price tag so i got a new aftermarket rad from the UK which is an alloy core and plastic tanks and it has a proper sealed in baffle to make the rad a dual pass and delivered for less than $200AU dollars i was as happy camper .
Now i can hold 100K in 4th running 265's and standard ratios pulling my camper loaded and a high loaded roof rack with the aero dynamics of a bessa block and it sits on 88deg all day
Best thing i did was to fit a new rad when i had the motor reco it now pulls great and i have no heat problems :D

[Blknight.aus]

some people block that hole completely, please dont.

fit a washer over it with a small hole in it .

IF you're not going to ever visit the high country in winter or take the vehicle anywhere where it might get a frozen radiator then feel free to blank it completely. In the event of a frozen up radiator the hole serves to permit some coolant flow while the center cores remain frozen.

In just the right circumstances its possible to overheat an engine in Icy conditions if the radiators frozen up.

[mudder110]

hi had the same problems with my 300tdi 110 fitted a new radiator with a extra core row towed a ton and a half camper plus work tools through wet black soil in the gulf for 2 days winching and digging hills mud you name it
hottest she got was about 85 on the vdo. normaly sits about 78 at 95 kmh
towing sits on 80 done 30000ks since then, just got back from point parker near Doomadgee some hell rough tracks and big hills around there .
still runs cool as a cucumber, I highly recommend the extra row on the core
and I use a 50/50 coolant mix changed every 12 months.
regards mudder110.

[rainman]

Just a quick update for anyone interested....

This is how the 130 is looking at the moment.

https://www.aulro.com/afvb/images/imported/2013/11/1516.jpg

https://www.aulro.com/afvb/images/imported/2013/11/1517.jpg

https://www.aulro.com/afvb/images/imported/2013/11/1518.jpg

Since posting here I've had an Adtrad 4 row core put into the radiator, and played with all sorts of things like running without the thermostat, bypassing the heater matrix , etc, etc. The last thing to do was to pull the head. The gasket looked completely intact, and there are no visible signs of cracks or coolant anywhere on the head. So, tomorrow the head goes in for crack testing. For reference, it's a South American head that is 9 years and 110 000 km old.

James.

[Tank]

Not easy to tell, looking at a pic, but it looks to me that combustion gasses have been leaking from #2 across to the nearside of the block and also into one of the water jacket holes, how's about a pic of the combustion side of the head, Regards Frank.

[justinc]

^^ what frank says. i can see at least 3 suspect places. can we see closer pics of head gasket, head and block face?

jc

[rainman]

You're right. The leak across from number 2 ties in with exhaust residue down the side of the block. It was there when I replaced the manifold and turbo and at that point I assumed it was the manifold gasket. 18 months after installing the new gasket and manifold it's still there. This is a pic taken during the turbo installation:

https://www.aulro.com/afvb/images/imported/2013/11/1453.jpg

Stupidly I didn't take a shot of the face of the head and it's in for testing now. I'll take some gasket and block pics tonight.

Thanks again guys :BigThumb:

[justinc]

:( that exhaust residue is more likely from a leaking slip joint where the manifold branch connects to the centre piece.

keep looking.

jc

[rainman]

Here are some more detailed pics. The head was confirmed this afternoon as 'not cracked' and in fact in generally good condition. It's going to be faced and have a valve seat grind done.

Gasket top side:
https://www.aulro.com/afvb/images/imported/2013/11/1414.jpg

Gasket underside:
https://www.aulro.com/afvb/images/imported/2013/11/1415.jpg

Suspect number 2 area, top side (there's definite discolouration on the ring around bore hole):
https://www.aulro.com/afvb/images/imported/2013/11/1416.jpg

Block:
https://www.aulro.com/afvb/images/imported/2013/11/1417.jpg

https://www.aulro.com/afvb/images/imported/2013/11/1418.jpg

James.

[justinc]

that is a strange way to fail for a tdi, and thats pretty much the most obvious blown tdi gasket i have seen for a while, best check the block face too for level, and wasn't there at least a small choofing sound with all that gas leak through the fire ring of number 2????


jc

[rainman]

that is a strange way to fail for a tdi, and thats pretty much the most obvious blown tdi gasket i have seen for a while, best check the block face too for level, and wasn't there at least a small choofing sound with all that gas leak through the fire ring of number 2????

No choofing sound I'm afraid Justin. I hope to get to cleaning up the block and checking for level tonight.

James.