Mystery P38 problem.... Circulation / overheating...

Turtled said:

, no idea if pressure cap is faulty, but it seems to be doing its job.... up to a point! How tight should it be on?[/FONT]

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Pressure cap should be on very tight, there is a tight spot on mine before it is fully home. You seem to be ignoring the possibility that the water pump is shot.

Datatek said:

Pressure cap should be on very tight, there is a tight spot on mine before it is fully home. You seem to be ignoring the possibility that the water pump is shot.

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Water pump is new....

if the heating goes off in the car , this is a sure sign of a cracked block (along with all other symptons) I got my block lined, problem solved but pricey

Here`s an idea, but maybe not a good one, take out thermostat, take off top hose, (engine cold), start engine if pump is good, water should shoot out everywhere. Only need to run for 30secs to check. As Datatek says it sounds like a waterpump failure, although you say it`s new. Relatively easy quick check to eliminate this possibility?
Also as said before on this thread, (sorry can`t remember who) there could be a manufacturing fault in a new rad. As a way to check this, maybe, take off both hoses, fill with hot water from top, and check it`s warming evenly as the warm water flows thro??
I`ve not tried this myself, just throwing ideas out for comment.

Have you tried bleeding the heater matrix as air trapped there would restrict the flow of water and overheat the system.

Exactly the same issues as I've had for the last 2 years!!! You gotta bite the bullet friend, you have a cracked block and/or a slipped liner. Simple as!!!!

have you noticed any sort of misfire on first start up in the morning ?

wil2813 said:

have you noticed any sort of misfire on first start up in the morning ?

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Now you mention it, yes. Not always, but I have noticed on several different occasions it hasn't started 'first touch' like it always used to.... Does that tell us something?

Looked at your spark plugs lately?? What colour are they? All the same except one nice clean one?

Was the new thermostsat a copy or genuine? I've had several issues with copies, bad circulation, leaking housings, either straight away or after a very short time. Only use genuine these days and have never had an issue, including several treks through very hot climates. And don't make the mistake that I did and think £30 buys you genuine, they're about £40 dearer!!

gtland said:

Looked at your spark plugs lately?? What colour are they? All the same except one nice clean one?

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I checked the spark plugs last week, looking for just that, but all plugs looked normal to me - and the same as each other.

fortgrange said:

Was the new thermostsat a copy or genuine? I've had several issues with copies, bad circulation, leaking housings, either straight away or after a very short time. Only use genuine these days and have never had an issue, including several treks through very hot climates. And don't make the mistake that I did and think £30 buys you genuine, they're about £40 dearer!!

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It has had 2 new thermostats. The one I fitted was from Island 4x4 on ebay. I paid £20. That is the current one. I still have the previous one, but I don't think that was a genuine part either - but it was more expensive....

Anyone else think this could be the problem?

Having a look through your thread and after my 3.9 has just recently been over heating which I solved (thermostat sticking and not opening properly)

If your top hose is warm then the thermostat is opening as the flow of water comes from the engine to the RAD via passing through the thermostat. There's a sure way to test if it's the thermostat is the culprit......... Take it out and just run without it. It'll take a bit longer to get upto temp but if it still overheats then you know it's something else.
After replacing my thermostat I had another issue. No heat coming through the heater inside and my LPG pipes (that are usually very warm very quickly) where cold all the time. I then put all the caps back on, expansion and top RAD plug, let it build a bit of pressure (5 mins or so), took RAD plug back off, topped up with water/coolant as I revved the car to draw the water through, pipes then became warm and heater working due to an air lock that was in the system.

DC_ said:

Having a look through your thread and after my 3.9 has just recently been over heating which I solved (thermostat sticking and not opening properly)

If your top hose is warm then the thermostat is opening as the flow of water comes from the engine to the RAD via passing through the thermostat. There's a sure way to test if it's the thermostat is the culprit......... Take it out and just run without it. It'll take a bit longer to get upto temp but if it still overheats then you know it's something else.

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The configuration of our engines is obviously a bit different.... on mine, the thermostat is located near the bottom of the rad, and is like a cream coloured plastic cylinder with 4 pipes coming off it. You can't get to the actual thermostat to remove it, it is sealed-in to the unit. I guess I could try drilling it as has been suggested in an earlier post, but I can't think of an alternative non-destructive way to test....? Will the car run ok if the stat is removed?

Ahh right I see now the P38 is a sealed unit? The car would take longer to get o normal running temp ye's with it out not too great in the winter but worth a go to eliminate each thing one by one IMHO

get a screwdriver and force the center spindle of the t/stat to one side so that its permanently open.i could get about 10 miles before engine overheated with t/stat like this

i had every thing you have with yours done every thing you have done even pulled the heads off gaskets looked ok liners looked all in the right place none were uneven no steam cleaned pistons but still had to replace the engine due to a crack behind a liner,irontite didnt work either nor k-seal,

So, taking all of the replies into consideration, I'm now moving towards thinking it must be either a failed head gasket, a slipping liner, or a cracked block (joy!).

I've just got another car for the missus, so I'm going to hang on to her old one until I've sorted the Rangie.... so it is now my hobby rather than my car!

What's my next step? Do I try the k-seal route, or is this likely to ruin my new radiator? Do I take the plunge into taking off the heads and having a look at the HG, or should I try something else first?

I will be keeping the car, and will sort the problem one way or another, so I don't want to do anything that might have a major downside....

k seal will not work you could try irontite if your looking for a short term fix, if not start looking round at engine prices. for a new short end your looking around £2,000..

hi some garages have testers for combustion gasses in water .2 when running leave cap off and see if water boils smokes and keep topping up give it a rev now and again while topping up air locks will blow water out header tank and make shure heater is on hot .3 look in the header tank were the bleed pipe from the rad comes in it should have water pumping in ,lots of bubbles means air pumping from some where(head gaskit or a crack if filled with cold water to quick after over heat)4 small bubbles will quikly fill top hose to rad with air ,hot air, and stop water flow to rad ,and when running wi cap tight check if rad hoses go hard and pump up, again presure buld up due to poss gaskit fail,like some one else said copper k seal might have been used to cover it up ,previous to you.and heater going cold when on hot shure sighn of gaskit ......

try irontite if anything, follow instructions to the letter you need to flush all anti freeze out before starting,if this works still look for a new engine as its a short term fix/bodge

clarkie said:

try irontite if anything, follow instructions to the letter you need to flush all anti freeze out before starting,if this works still look for a new engine as its a short term fix/bodge

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holts wonderweld is the only medicine if you dont want to spend 2k,you will be back on the road in 30 mins,it will give you time to source a new engine