head gasket issue

[frenchdave]

Hi
we have just purchased a tf 135 with 52k miles on it.
It was low on coolant, and a sniffer test confirmed exhaust gas in the coolant.
We removed the head and had it skimmed. The shop doing it said it was low on one side, but skimmed it ok. There was no sign of fire ring indentation on the head.
Cleaned the block that was already very clean , using a a wet and dry paper.
The liners where low, but not level.
We had a choice and went for the MLS with a shim.
All back together, and the car is burning coolant, and the sniffer test shows up straight away that gases are in it.
Where did we go wrong.
Used new bolt etc. Starting to think the torque wrench could be out of calibration, or did we put small scratchs on the block? Or will a car with low liners fail to seal and therefore we should do it again and use the single gasket and no shim.
Otherwise we could buy a gosney head saver shim, and put on a single rather than MLS gasket.
It is a nice car , and do not want to give up on it.

[frenchdave]

saying liners low means there was a small bit of proud but not much

[talkingcars]

Why did you get the head skimmed? Was it warped?

[frenchdave]

didn't know if it was or not, but the shop thought it was low one side so in effect it was. but only took off a very small amount.

[Geoff.F]

Did you peen the face after machining ??
Did you pressure test it ??
Do not understand why you query the torque wrench. Without my looking at figures. the initial low torque ensures it is clamped. A angle index is then used in two stages to stretch the bolts and obtain the final required clamping load.
Geoff.F

[Mykel]

Head gone soft? From my experience, if it needs a skim due to indentation of fire rings, it’s soft as cheese cake and not worth any efforts. Exhaust gas blow off into coolant being the usual sign.

Getting a replacement head would be my suggestion.

[frenchdave]

didn't have any indentation marks before the skim. I did say that in the original post

[Mykel]

Ah, sorry Dave, missed that. Did you check the liners for movement inside the block? I always try to turn them (quite thoroughly) when the head is off to make sure they have not come loose on their seats. If they have, there can be movement under load and they will “hammer in” the fire rings.

[frenchdave]

will check liners when we take the head off again.
Have you ever seen scratchs from wet and dry stopping the new gasket from working? I haven't, but wondering if thgis could be what went wrong?
Any ideas welcome

[Mykel]

Usually I use a scraping tool (for glass ceramic cooktops) very, VERY carefully to remove all remains of the old gasket on both the head and the block, then clean everything off with 600 grit paper. Never had any issues with this.

[frenchdave]

could it be that we have not gone the full half turn twice on the head bolts? after the inital torque?
I am heading to trying one of these and checking the liners to see if we have a mover.

http://www.gosnays.co.uk/acatalog/SaverShims.html

[frenchdave]

Have been out looking and driving the 135
Have refitted second new head gasket this time a oem as the liners are low.

At start up it does smoke a bit, but after driving round the lanes, that stops once up to temp, so i am happy it is not burning coolant. There is no smoke and you can rev it high and nothing is being burnt

However you can watch the coolant go down.

there is no change in the oil level.

Therefore the car must have an external leak that we cannot find as it does lose fluid.

Rad looks fine as does the pipes running to it

Where should we look. My thoughts are first the heater matrix. there does seem some moisture in the foot wells, but the design of the heater keeps that area clear. i think we should remove the center consul and look at the pipes both metal and rubber to search for leaks.

Also it may be possible that the water pump hasn't sealed, and you cannot see the fluid as it drops on the exhaust and burns off? My hunch is heater matrix If I get time Sunday i will take out the center consul. I think the metal pipes to the matrix run inside the car. Could it be that a leak there would take the fluid in to the sills? where it sits?

Will investigate

[talkingcars]

You might have to do a pressure test on the coolant system.

[frenchdave]

ok but if i do that, and i cannot see where it is losing it, do i assume its internal? even though it dosn't smoke or seem to be going in to the oil?

[Geoff.F]

There are 2 "Technical" methods to determine where there is leakage.
Put some flourescent dye in the coolant, pressurize the sytem to 15 Psi and then search for leaks with a UV light.
You will not want to use the 2nd method which is to use a radioactive isotope and a geiger-counter.
A simpler way is to clean suspect areas with WD-40 to remove the grease and apply white chalk either by scrapping apiece of blackboard chalk or the deluxe way by using a Crack Detection Chalk Aerosol.
Geoff.F