Overheats with thermostat in.

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I spent most of the day with the guy who fitted the engine yesterday and he's adamant that the head gasket is okay as there is no evidence!!! He added some k-seal and replaced the stat again. Still over heating. The stat isn't opening at all. and the water around it is cold. What her reckons is happening is that the water in the head is boiling before the stat opens then cold water rushes in and instantly turns to steam on the hot engine which pressurising the system. Anyhoo he drilled a hole in the stat with a 4mm drill and now it's running cold again.

Does any of this make sense and why is the stat not opening.

ta
 
I'm no expert but sounds a bit like bollox to me!!!!
Don't see how collant in the system can turn to steam unless you've got air in it, basic physics int it?
Seems to be a fair amount of folk on ere who think it's your head gasket.
Praps matey don't want to admit it cos he'd have to fix it.
As I say I know nuffink so my opinion aint worth feck all.......
 
KTMRider said:
I'm no expert but sounds a bit like bollox to me!!!!
Don't see how collant in the system can turn to steam unless you've got air in it, basic physics int it?
Seems to be a fair amount of folk on ere who think it's your head gasket.
Praps matey don't want to admit it cos he'd have to fix it.
As I say I know nuffink so my opinion aint worth feck all.......
Click to expand...

Any liquid will turn to steam if the temperature gets high enough. The point is not whether there is air in the system but why the engine is getting hot enough to boil? A simple test for air on the system, is to run it with the expansion cap off if there is air you will see the bubbles in the expansion bottle.
 
Get an infrared laser thermometer. They are about £20. Run the engine up to temperature and check the temperature at various points around the cooling system as it rises. It sounds to me like your mechanic is better at talking bollox rather than fixing cars.

Here's a couple of simple questions to ask him.....

1) what temperature (deg celsius) does water boil at?
2) what temperature (deg celsius) should the thermostat open.

Please ask him and post his honest replies on here. He shouldn't need to look it up. If he does then it proves he didn't know when the thermostat should open in the first place.
 
seeing as the coolant had bits in it from the dying rad i wonder if some of the waterways have become blocked and therefore not allowing coolant to flow fully
 
Sean said:
seeing as the coolant had bits in it from the dying rad i wonder if some of the waterways have become blocked and therefore not allowing coolant to flow fully
Click to expand...
Now this is what I'm thinking. I put a new stat in last night with a 2mm hole drilled in it. The temp guage showed hot but not critical in the red. I felt the pipes and the top hose was hot which goes into the thermostat housing. The small right angled pipe which comes out of the bottom of the thermostat housing was hot but the bottom hose was cold.

What gives. None of the pipes were pressurised.
 
Beaver said:
Now this is what I'm thinking. I put a new stat in last night with a 2mm hole drilled in it. The temp guage showed hot but not critical in the red. I felt the pipes and the top hose was hot which goes into the thermostat housing. The small right angled pipe which comes out of the bottom of the thermostat housing was hot but the bottom hose was cold.

What gives. None of the pipes were pressurised.
Click to expand...

sounds like the mechanic is a prick, and the guy above is on the right rails. If the radiator and system was full of **** then a chance that the water ways between the head and block are blocked, so get the head off and check it out, it aint a big job and if it's overheated a trillion times then the starting point for me anyway.

I dont like engines full of rusty water, usually ones like that are terminal coz the alloy and cast etc react together and kill it. Personally I avoid engines like that, if the rad is full of rusty water then I look for another one.

Whats the next plan for the guy, fokin air cool it or sumut.
 
The head has been pressure tested, skimmed and a new gasket fitted. It still over heats over 50mph or when under heavy load. My mechanic friend has a 300tdi that he is now going to put in once he's got a prop shaft for it. He thinks the block liner may now be causing the problems.

Now the head (hopefully) has been ruled out, any new ideas what could be causing the over heating problems. As I said earlier it runs fine without the stat out but I need the heaters at this time of year.

Cheers.
 
Sorry that sounds a bit over the top changing the engine!

It does sound more like the headgasket has blown. You said the head was pressure tested how? On the block or off? should be done on the block.
get the head off and get it checked at a machine shop or go to a another garage and ask them whats wrong.
 
Sean said:
on a 200 engine ?

he's bull****ting you, find another mechanic before he empties your wallet
Click to expand...

I need to agree with Sean, "pish", you are going around in circles here get something that can detect gases in the water. Also you took the old gasket off, did you check the block, gasket and head for leakage, and place a straight edge over the block.

The only other thing I can suggest is get some of that stuff that detects cracks and spray both the head and block, I have used this and it's good, comes in two bottles. Can't remember the history now but I hope you have used new head bolts, or at least made sure they aint too long and fooked.
 
Sean said:
on a 200 engine ?

he's bull****ting you, find another mechanic before he empties your wallet
Click to expand...
He's fitting the engine for free so I'm not out of pocket. He can't work out what's wrong with it so he's cutting his losses as well as mine so no more money is thrown in to it. AFAIK the head was sent away for pressure testing and skimming at his own expense. There were 4 fractures in it but it still passed the testing and was declared fit for purpose :confused:

I'm no mechanic but I'm stuggling to understand what's wrong with it and would like some peace of mind. I'll accept the 300tdi gracefully though.:)
 
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