Engine headgasket?

[driver]

Hi all ,

Thanks a lot to those who replied to my question. Although I don't seem to be any closer to solving the problems.

I'd like to ask another quetion; My engine at the moment after starting seems to get hot VERY quickly and then blows a constant stream of bubbles into the expansion tank, I have a short neck radiator with a seven pound cap. I have been told it's the headgasket that is faulty?? I have carried out a compression test on all of the cylinders and they all seem to range from 155-170.

Can anyone tell me if these figures are correct?

And what may be happening to cause these problems?

 

Thanks very much, in anticipation.

 

I'm a little slow on this you may have guessed, but i'm learning- and my daughter is a star!

 

Cheers

[blgdave]

Hello

 

Dont know what you have tried already? But there are a few steps to take in order to lok into your problem by process of elimination...

 

1. Remove your Thermostat and run it with non fitted. It should take for ever to get warm and not over heat if the thermostat was sticking. While the car is ticking over, go boil the kettle...No not for tea! Drop the removed thermostat into a cup of boiling water and see if it opens, you will see it move. Or even boil it up in a pan and see what temp it actually starts to open at. Wives love this job being done by the way!! If it does not open then spend your 4 quid on a new one and hey presto fixed!!

 

2. A big guess as I have not done a Triumph as yet, but my guess is that its an old style mechanical vane water pump. Remove the water pump and take a look at the gaps between the vanes and the housing. They may have worn to an excessive gap and not be circulating enough water through your system. Or it may have broken down all together and be jammed solid? If its either then fit a new water pump.

 

3. Radiator core blocked. Let your car run upto a nice warm temperature and have a good feel about around the back of the rad. It shoul dbe an even temperature all over. If there are any spots that feel cooler than the rest then you have a blockage in the core and insufficient water is circulating and so the rad is not working at maximum capacity. Try to back flush the rad with water and see what gunk comes out of it. re-fit and retry if you think you shifted it. But best to just get your local Rad shop to fit a new core. Will be sweet as a nut after!

 

4. Doing your compression test should tell you if the gasket is blown from the cylinders out over. But you may have a leak at one of the water jacket channels. This will give you normal compression but still leak water. If its blown in the normal fashion then you will see a milky resiude from emulsification between the oil and water. Or it can blow between cylinders I suppose, but not that likely and then woul dnot effect the water?

 

5. Oops head is cracked. Best you go see the bank manager and cancel the summer holidays.

 

Hope this helps in laymans terms???

 

Cheers

 

Dave...

[marvmul]

4. Doing your compression test should tell you if the gasket is blown from the cylinders out over. But you may have a leak at one of the water jacket channels. This will give you normal compression but still leak water. If its blown in the normal fashion then you will see a milky resiude from emulsification between the oil and water. Or it can blow between cylinders I suppose, but not that likely and then woul dnot effect the water?

Dave...

This is correct if the gasket has an important leak. If it is very small, or only present at high pressure, a compression leak will not always show it, but the high pression of the

combustions will force burnt gas past the gasket. A test exists to show the presence of combustion products in the coolant. Bubbles in the coolant are very suspect of a head gasket leak.

[blgdave]

Yes of course, I forgot that one. Sorry folks. I actually had that test done on the TVR when the first engine went bang (oops!). They put a sensitive sensor affair screwed onto the top of the expnsion tank and it checks for exhaust gases.

 

Swapping a head gasket I would assume is a relatively simple task? NOt done one on a TR but the gasket was swapped on my Crossflow Escort three weeks agon in a field with minimal tools and a borrowed gasket. Took 1 hour 30 mins from engine off to engine on again. That was with beers in hand also! Mind you my mate Steve did all the spanner work, would have taken me a fair bit longer! Still not a hard job to do.

 

Are these Tr engines similar in design to a cross flow ford motor, in that tappets will need setting after to account for the thicker gasket? Not had one to bits (YET!) so bow down to everyone elses experience.

 

PS> I am no mechanic, I just liek getting oily!!

 

Cheers

 

Dave...

[kob666e]

The only way to find out what is happening is to take the head off, you will soon know if the gasket is blown, and it is a relatively easy job. If there is a crack in the head, well that's a different kettle of fish I'm afraid.

 

And yes, you should check tappets after a head gasket change or re-torquing the head.

[Rhodri]

Dave, it is a lot easier to change a crossflow head gasket. The TR head weighs about 50lbs for a start, and you have to watch for the wet liners moving- that will give you a load more work if they do, as in removing the sump, con rods and pistons to replace the figure of 8 gaskets ! There is also a bit more room round the manifold area on the Ford, I think.

If everything goes OK, then it shouldn't take much longer to change the TR gasket than the Ford. Hopefully no damage will be found that caused the gasket to fail.

[marvmul]

The 4 cylinder has wet liners : to make the gasket seal, the liners should protrude above the block everywhere between 0.10 and 0.15 mm, AFTER provisional torqeuing the head

to about 100 Nm, this is not critical. If the liners are sitting too low, the gasket will fail, if they are too high (0.20mm or more) the coolant will escape.

[Bully]

Driver,

 

your problem, if I am reading right, may not be one of a head gaskit but an overheating problem?

 

I had a similar problem many years back with my TR4A, which constantly overheated. I removed the thermostat, and fitted a lenlow fan, but still overheated. I checked the water pump, tested compression and tested the radiator - all were fine.

 

It turns out I had a blocked waterway behind No 4 cylinder. Over the years, when people had serviced the car, they drain the cooling system through the bottom of the radiator. However, water enters and exits the engine from the top of the block, and unless you use the drain tap on the side of the block as well, the sediment builds up in the block, and normally around the back of no 4 cylinder.

 

The water at the back of the block cannot move, boils, and returns the way it came in. A clean give away, is although the top of my radiator was overheating, the bottom hose was cold !

 

I would recommend draining the system through the block to see if you have the same problem. Remove the tap all together from the block, and run a hose into the top of the rad - you should get a good flow out of clean water. Try to dislodge and sediment with something like the end of a cable tie - it's tight in there, so poke it around sideways.

 

If you are getting nothing, then you have a blocked waterway. You will need to take the head off, and spoon out the sediment.

 

Worth testing before you try anything else.

 

regards

 

Bully

[TR 2100]

Many good possibilities on some of the more unlikely causes of your problem,

but suggest you consider the basics first.

 

AlanR

[driver]

date='Jun 9 2008, 10:02 AM' post='95799']

Driver,

 

your problem, if I am reading right, may not be one of a head gaskit but an overheating problem?

 

I had a similar problem many years back with my TR4A, which constantly overheated. I removed the thermostat, and fitted a lenlow fan, but still overheated. I checked the water pump, tested compression and tested the radiator - all were fine.

 

It turns out I had a blocked waterway behind No 4 cylinder. Over the years, when people had serviced the car, they drain the cooling system through the bottom of the radiator. However, water enters and exits the engine from the top of the block, and unless you use the drain tap on the side of the block as well, the sediment builds up in the block, and normally around the back of no 4 cylinder.

 

The water at the back of the block cannot move, boils, and returns the way it came in. A clean give away, is although the top of my radiator was overheating, the bottom hose was cold !

 

I would recommend draining the system through the block to see if you have the same problem. Remove the tap all together from the block, and run a hose into the top of the rad - you should get a good flow out of clean water. Try to dislodge and sediment with something like the end of a cable tie - it's tight in there, so poke it around sideways.

 

If you are getting nothing, then you have a blocked waterway. You will need to take the head off, and spoon out the sediment.

 

Worth testing before you try anything else.

 

regards

 

Bully

 

hello

thanks