2.5 n/a D Still overheating!!!!! Arrrrgghhh!!

is the radiator actually getting hot?, and have you tried it without a thermostat in to rule that out as a problem.

Even with a stuck open thermostat and a waterpump that wasnt spinning properly (lost the key in the bottom pulley so it wasnt turning the belt properly) my 2.5 didnt even get up to normal (with thermostat) running temp after dual carriage way cruising.

It does sound like something serious could be up with it.

>

My 200Tdi still does similar...

I have put on a new viscous coupling, replaced the radiator (that was about 5 years past knackered), and new stat, water pump is good. There is no trace of oil in water or water in oil and it still climbs nearly to the red when driving along the motorway.

I have read 2 things that it could be of late - collapsing bottom hose and blocked cores in the block.

So I too would like to know how to clean / clear the water jacket.

Also, how do you tell if the bottom hose is collapsing under suction? Would I see it if someone rev'ed the engin whilst I watched it?

Thanks Jon

I have replaced all the hoses in the engine bay. Top, bottom and heater hoses. Radiator gets hot on one side (from top hose) and is stone cold on the other. I would at least expect it to be luke warm when the engine is hot, if water is circulating. If I run with no thermostat temperature reaches about

1/3 of the gauge. I would expect hardly any movement f circulation was good.

Stew

Do a compression test, my money is on the head gasket failing. probably between two cylinders.

Had Similar on Percy when I got him (2 1/4 engine in those old days).

I did have reduced performance though - even for a sIIa.

Lee D

wouldn't a failing head gasket produce some sort of smoke or performance deterioration? I have niether!

Stew.

On my IIa it did but that was between 2 cylinders and a fair ole in the gasket too.

On my VM it made no difference that was noticeable to the drive. I chould however hear the the chuffing under acceleration.

Have you checked the injectors too?

Lee D

You say the gauge is ok. What about the temp sensor in the engine. Forget the Kenlowe and just look at what the landy is telling you. Engine is running well and everything else is ok, but the gauge is telling you it is overheating. Yours Gmacz

In news: snipped-for-privacy@4ax.com, Tom Woods blithered:

Usually better to do it t'other way round. In @ bottom hose, out @ top, ie back flush it.

If you havent already tried, then with the 'stat out, and the bottom hose detached, stick a hosepipe in the top hose and run it through the engine. See what comes out.

That doesnt sound too unreasonable.

Are you positive your thermostat is opening properly?. Most have a little hole in and let a small amount of hot water past even when closed - so perhaps this is why your radiator is only getting slightly warm. Another new thermostat only costs a few quid and is easy to try. I have had a fair few that have been faulty 'out of the box', so i reckon its worth double checking!

Also - have you sat and watched the engine to check if the fan belt is spinning properly?. I lost the key on my bottom pulley so it didnt spin properly and it wasnt until i'd replaced the alternator and it hadnt cured my dead battery problems that i noticed how slowly the belt was spinning! (there was a small amount of friction that caused it to spin just fast enough to make the charge light go out - but it never sped up with the engine!) This also explained my warmer running that week! (water pump wasnt turning at full speed)

I think one of my cars has a cracked head/dead gasket as I have bubbles in the expansion tank. (the oil is fine) With no thermostat in that still gets hot very quickly at tickover.

No - in at top to back flush - the original suggestion was correct.

That'll back flush the block but not the radiator.

The Kenlowe stat was set when the temp was okay according to the gauge. I know the engine is too hot and not cooling because the Kenlowe does not switch off, because as the gauge says, its too hot! I have tried flushing the block several times in both directions to no avail. Stew.

He says he's put a new radiator on it, so that should hopefully be clear.

On or around Tue, 26 Apr 2005 22:14:34 +0100, "90ninety" enlightened us thusly:

OK, so you tried running it seriously with the stat out, and it got to 1/3 gauge?

I reckon the stat's iffy - I've had new ones that didn't perform according to spec.

if it's working, the engine will get to near-normal operating temp without the stat. When idling or pootling along, it'll cool down again.

If it gets to normal temp at *idle* with no stat, then you have problems.

I took it for a very long run with no thermostat yesterday at speeds ranging from standstill to 65-70mph. It gets hot enough to turn the cooling fan on (about 2/3rds up the gauge), but does cool down again with the help of the fanm to about halfway. I tested the old stat in a pan of water with a calibrated digital thermometer, it opens at exactly 82 deg C but not very much. The new stat I did have fitted is marked at 82 but opens at 84 deg C, which is okay, and it opens much wider.

Stew

On or around Wed, 27 Apr 2005 09:36:22 +0100, "90ninety" enlightened us thusly:

doesn't sound too far off, for an NAD - I suspect they run hotter than the TDi; also, it might well be that the rad is smaller than the V8 ones - my

110 was originally an NAD and when I finally got pissed off wiht it overheating and replaced the rad, the resultant new one was a good bit fatter. In fact, that's possibly a useful upgrade to the diesels - fit a V8 rad...

once the temp is a few degrees over the rated temperature, it should open pretty much fully - takes a minute or so to do so.[1] One that doens't open fully is definietly suspect and will seriously affect cooling under load.

we shall wait and see :-)

I trust the replacement rad was the right sort...?

mine runs about a needles width over a quarter with a new stat. At the mo I'm running with no fan on the engine and it stays under half. I had the radiator covered up in the winter, work and back it didn't go over half. when I went down the motorway it didn't take long for it to shoot up to 3/4 at 65 so I had to slow down.

put a new stat in (was cold wanted more heat) mine when I got it and had the rad recored (it fell to bits and leaked like a sieve)

Jon (85 90 nad)