P38A overheating

This kind of indicates an airflow issue. When you're moving air is forced in by the forward motion. However, it could also be the water pump, or a loose belt somewhere.

To check air flow, try idling and then turning the heater on full blast. If the guage falls, it's due to the increased surface area of the 'cooling' system (as some heat is being taken out by the heater, if you see what I mean!).

Also check fluid level in the rad, try to find any cold spots on the rad (which could indicate a blockage somewhere).

It's built by Land Rover - where's the surprise? :-)

Martyn

With my experience, I´d tip on the visco coupling/fan.

Dan> Normal driving does not cause it to overheat although the Dan> temperature needle does hover around the hot side of the Dan> gauge. However if it is stationary and idling for any amount Dan> of time it overheats.

Dan> I have checked and the fan is turning when the engine is at Dan> idle. In addition when I rev the engine the temp needle comes Dan> back down to a normal temperature. The temperature needle Dan> seems to move around quite quickly compared to other cars I Dan> have owned too.

Mine is fairly steady in the middle of the range.

Dan> Could this be the water pump on its way out? or the Dan> temperature sensor?

I guess so - bear in mind that the engine ECU has a different coolant temp. sensor and the only way to reliably find out what it's reading is to interrgate the GEMS ECU with a diagnostic tool - though you can do some basic resistance/voltage checks with a multimeter.

Dan> I was quite surprised when it did overheat that the computer Dan> thing did not bleep at me as well (it will bleep if the Dan> washer bottle low but not if the engine is about to die from Dan> overheating?).

You expect consistency in the design from Land Rover? Come on! :-)

This might sounds like a silly question: is it actually overheating (clouds of steam, loss of coolant, all the stuff)? Or just the needling jumping around?

I ask this question because the relationship between actual coolant temp., coolant temp. as seen by the GEMS Engine Management system, coolant temp. as seen by the BeCM, and coolant temp displayed to the driver is fairly complex.

If it is really overheating, then suspect either rad blockage (water or air flow), or the viscous coupling on the fan which could be wearing out (I have a new one in the garage to fit to mine). If it's just yanking your tail, let me know, and I'll dig out the ETM and tell you where to shove the pointy bits of your multimeter. :-) I've not heard anything failing in this area, but that doesn't prove anything.p

Going back to your original post, it sounds like it really is overheating. There is some information on the fan VC on my site at

AndyC

--

+-------------------------------------------------------------------------+ |Andy Cunningham aka AndyC the WB | andy -at- cunningham.me.uk | +-------------------------------------------------------------------------+ | - Everything you wanted to know || about the P38A Range Rover but were afraid to ask. |+-------------------------------------------------------------------------+"The world has gone crazy: The best rapper is a white guy, the bestgolfer is a black guy, France is accusing the US of arrogance, andGermany doesn't want to go to war." -- Anon

The P38a has been known to have water pump failure, the plastic impeller (well thought out design!) shears from its shaft and consequently pumps no coolant!!!! We've seen this at my work, erratic temp and running hot with the above to blame, our next door landrover dealership has also experienced one or two failures/repairs........of the same!

Good luck

Lee!

When did Land Rover implement this?

I've still got a rather nagging suspicion that the overheating on Grumble is in part due to the water pump - although the one on the

4.6L V8 (which came out of a 2000 Range Rover and only had 3K on the clock) is now actually the one off the original 3.5L...

My theory was that perhaps the pump drive was slipping on the shaft - although I have no evidence to support this... I really should try to do a good flow test I guess.

There's bugger all else I can think of to do - other than opening the guage housing and bending the needle a little to the left... That'll cure it :-)

Martyn

Martyn,

I've a 4.6 V8 in Piglet now, and after cleaning my rad (gosh, how did *all* that mud there!) all is hunky dory.....however....I still have the 3.9 fuel system on the top and the "front" from the 3.9 (so I can have me Dizzy!).....

So...no more overharting problems for me.

with mine, too : replacing the visco coupling/fan solved the problem (on a 2,5 DT)

Michael.

Nope - got a new rad, recored with large cores, all tested... :-(

I'm fairly sure that bending the needle will do it...

Martyn

I'm going to see a 4.6 V8 tomorrow, so maybe I will be joining the club! Quite exciting, for me at least. Just hope it's not a dog.

David

How about soldering a resistor inline?

If there's one thing that's better than a V8 - it's a 4.6L V8 :-)

(Erm, although I have just got a 5.2L TVR lump...)

I'll keep my fingers crossed for you...

Just think of the friends you'll be making in the local filling station :-)

Martyn

On or around Fri, 24 Oct 2003 15:35:16 +0100, Mother enlightened us thusly:

wouldn;t make any difference on mine, the bloody heater doesn't extract enough heat to make a difference...

Anyone know if the new-type plastic Defender heater box has a bigger/better element in it? It looks as though it'd fit as a replacement for the old tin one I have. It's a non-trivial task to replace the element in the tin box, involving silly amount of rivet-drilling and so on, and no guarantee that it'd actually be better, even assuming new elements are available.

Been down this road myself with the old 3.5 (now have a P38a 4.0, no probs so far- x-fingers!); Had a 5-core tropical radiator in it, so that came out for a clean- to NO AVAIL. Replaced vicious coupling (well I thought $400AU was rather vicious) to NO AVAIL. Put the old one back, & did a chemical clean of the block- which did the trick.

Overheating is the last problem I am having at the moment, overcooling more like.

As soon as practicable I intend to replace the fan with an electric one.

I assume that it will pay for itself over time.

Thanks for all your help / suggestions.

In answer to some questions:

I have not let it/ it does not overheat to the point of steam /killing the engine.

The water levels are fine, the fan also seems to match the speed of the belt/ engine so it wouls seem the belt is not slipping / the viscous joint is ok. (someone did mention that they hae the overcooling problems, I know a fused viscous joint can cause this)

The heater on full wack does not make any noticable difference.

I notice that it has another matrix in foront of the radiator, I assume this is an oil cooler (I have no workshop manuals yet). I have just noticed that this has 2 electric fans are these standard? I assume if these are broken then this could well be the cause. I.E. not enough air flow when stationay.

I am lucky in that it is still under warenty from the garage I brought it from, so it will be going back this week and I will let you know what they find.

will let you know...

Cheers

Dan