How do I know if I have blown my head gasket???

[AZ88Turbo]

I thought I had figured out my overheating problems but after about 150 miles it has started again

It seems that what is happening now is; I fill and bleed the cooling system and it is fine for a while, but all the time it looks to be blowing coolant out of the overflow of the expansion tank. After so long then obviously it overheats. It seems to me that it must be getting pressure in from the cylinders but I have done a compression test and it tests out fine (all cylinders are just below 150). Is there any other way to know if the head gasket has blown?

Thanks in advance for any help,

Mark - 88 Turbo

[cnh1990]

First pressure test the cap to see if it is holding the correct pressure thats an easy fix if that is the problem. Then the next step is to pressure test the cooling system and check for leaks. What does the oil look like? Does the oil cap and dip stick look normal? Does the oil or coolant look creamy? Does the header tank have any bubbles when the engine is running? I'm not sure if you would be pumping air in the header tank like one gets in the radiator of a front engine car. A blown gasket might not show up in a compression check. Did you do a leak down test?

Calvin

[AZ88Turbo]

Hi Calvin,

The cap is the next thing I am going to try this morning, thought of that yesterday evening (but the parts stores were closed). The oil and water look fine (I have had several head gaskets go on my before, just not on a Lotus) and they usually blow in a couple of ways: water to oil (which gives the symptoms you mentioned), cylinder to oil (burns oil), cylinder to water (pressure in the system, which I have but also it always occurred that I would get steam coming out of the exhaust, which is not happening at all in this case, that’s why I am so confused with this one).

There are bubbles (or “plops”, not sure what else to call it) in the header but usually when it does this the water level goes down a bit so I assumed that is just the system bleeding air and replacing it with water, and it stops after a while. If I leave the top off of the header tank, after a while the water starts to back up and overflow out of it.

I need to do some more testing this morning but I hope to God I haven’t blown the head gasket because it looks like an “engine-out” job to me (changed a couple of head gaskets before on front engine cars with the engine still in, not that big a job, but it looks nasty on the Lotus).

Thanks again for your help. I’ll let you know what I find out.

Cheers,

Mark

[AZ88Turbo]

Here is the one I forgot: water to air I think this is it. I just noticed steam coming up from the back of the engine (looks like from under the cylinder block). I'm betting that the head gasket has blown arund there and is venting to air. BUGGER!

I can't see any pipes down there so I'm guessing that has to be it.

[superdave]

Is it anywhere near you turbo where the steam is coming from?
There are water pipes there I think to cool the turbo.
I was messing in this area a few months back installing a new actuator for my turbo and disturbed one of these pipes. I saw steam coming out throught a jubilee clip.

Cheers,

Dave Walters

[AZ88Turbo]

Ok, it's the head gasket. It just started blowing steam out of the exhaust now

Does anyone know what it takes to fix it? I have replaced head gaskets on other cars many times before and it is not a huge deal, but it says in the service book that the engine needs to be removed on the Lotus, does anyone know if it can be done without removing the whole engine? Or is that the only way??

Any advice is appreciated,

Mark – 88 Turbo

[rfoster]

I'm sure you don't have to take the engine out - I recently had the exhaust manifold replaced on my car with seized bolts and the garage managed to remove it with the head whilst leaving the black in the car without any problem - don't know if it's different for a turbo though.

[cnh1990]

Jim is the guy to ask on this one. We took his engine out. Just seems the eaiser thing to do. Take off the rear hatch anyways and see how much room you have. Do you have a lot of steam comming out exhaust? Mine spits out a little bit of water out the pipe and is just condensation. If you are convinced the other Minnesota club members have done numerous rebuild and will pose the question to them. Jim has been helping a new Esprit owner locally with front suspension repair and so has not been on line.

Calvin

[AZ88Turbo]

Hey Calvin,

I'm sure it is the HG, it is like a sauna in the garage now when the car is run, it got progressivley worse.

I have decided to take the engine out anyway and do a load of other stuff I have been wanting to do. Time for a clean-up me thinks.

Mark - 88 Turbo