Head Gasket

[de_stanny]

Hi All,

this week on the highway i saw that she was running warmer then usual, stopped at the next gasstation and check the cooling fluid ... empty ... filled her up again and drove to work, temp went back to normal , at lunch i checked again .... empty again but no water to be seen .... refilled opened the the filling cap and the water bubbelled out .... that seems to point out to be HGF...

Saturday started to pull the exhaust manifold lose... 4-5 hours later finally everything loose but i cant pull the turbo, exhuast manifold and precat out in one piece... the manifold hits the head near the CAS assembly ... is this normal ? i also found the leak that caused all this ,,, in the aluminium water pipe located at the fans there was a small hole by rubbing against the subframe of the radiator , will fabricate a sst one and tie it down in a good way ...

Where can i buy an original headgasket and the other gaskets i will be needing...

next weekend i will pull the inlet manifold and the head depending on the time as i am working outside in the burning Houston sun ,,, pfff to hot these time of the year ...

grtz,

de_stanny

[HJ2]

Are you sure that it is not just the hole in the pipe causing the troubles?
I would do a compression test the least before pulling the head!

By the way, i pulled the entire head, including intake manifold.
You can find virtually all info here in my topic:

viewtopic.php?f=37&t=19996


(and yes it is warm for hard labour).
Head gadgets can be found at rockauto (1991 Isuzu Impulse RS)

All the best!

[de_stanny]

hI HJ2,

I am pretty sure that its HGF , the 3 rd exhaust port on the head is clean , no black residu as on the other ports, so i gues a leakage from the combustion chamber to the water channel.
when you see bubbles coming out of the cooling water filling port , that points out to a leakage as discribbed above from my experiance with other cars.

the hg from rockauto is that one ok ? i did read that an original from Lotus is the way to go ...

thx ,

de_stanny.

[chrisP]

I would also check that the thermostat hasn't seized, I had a similar experience, when mine did. The water pump was trying to pump against it and pushing water out of the expansion tank (when I took the cap off).

Regards
Chris

[de_stanny]

hI Chris,

will check that aswell, the head is off in the mean time, i just replaced the thermostat a couple of months ago so it would surprise me that this would be the issue,

did i mention i found that the exhaust port of cilinder 3 was completely clean where the other ports where black from the exhaust gasses... that points to HGF to me ...

i am going to take the head to the machine shop today to have it checked out and milled if needed, will keep you posted,

greetz,

de_stanny

[de_stanny]

Update time,

had news from the head place , it needs to be shimmed and a few valves leaked a bit , so a valve job will be done aswell .

so next saturday rebuild time ....

grtz,

de stanny

[rip]

If the head is off, you've already done most of the hard work.
By now you'll know that the thermostat is dead easy to get at even with everything else in place.

[Brit-Car-Nut]

There is a maximum amount that the head can be skimmed. Don't let them just skim it as they might ruin it.

The service manual states 0.40mm or 0.016in but it might have been worked on before, so the minimum head height is 129.1mm or 5.083in.

If they go beyond those measurements, I think valves and pistons will foul. You can use MLS gaskets but they require a special surface texture on the head (15 to 30 RA?) and the block.

[de_stanny]

Hi Brit car nut,

The head was not worked on and had all info in my manual , the guys from the shop did a good job, some valves leaked and valve guides where oval ... replace and fixed all in one go .... was a Lille more expensive but worth it in the long run I guess....

The head and all stuff is back on in the mean time , only the turbo assay needs to go on on Saturday .... will be happy to drive my baby again ....

I did buy some waterwetter to reduce the temp as much as possible as I got temp of 38-40C everyday here in
Houston.
Additional question... I installed an aftermarket cooling fan with the 2resisters in series as with the original fan , is this really needs as the fan will not get full 12V...and will not give the max cooling flow I was hoping for ... in the past the temp was going up even with both fans running in slow traffic ... probably due to these high ambient temps.....
Greets,

De stanny

[de_stanny]

Hi all,

The head is back inn and she is running again.

The water wetter doesn't seem to make a diff ... think she is running on the temp reg of the thermostat... 1/4 of the temp scale ....

The resisters I have taken out on the aftermarket fan and the temp comes down a bit faster as before when the fans kick in.

Grtz from a happy elaner

[Peter D]

Did you use a head gasket set from Rockauto ?
They offer different brands....
Anyone with tips in wich one to use or to avoid ?

[de_stanny]

no i did order the original one , stil got the one from rock auto , didn't look that bad at all ...

[Peter D]

I asked my dealer for the price of a head gasket.
It's available for € 70,- incl. VAT. (Isuzu OEM)
At Rockauto it's appr. € 45 + shipping (€ 27,5) + VAT + customs for the complete upper head gasket set.
So I'll just list up what I need for a cilinder head revision and check prices at Lotus dealer before ordering across the ocean...
If I can get genuine parts at my local dealer for an acceptable price (let's say up to 20% more expensive), I will go for genuine parts.

[epipete]

Head gasket is £29.76 from SJ'S Sportscars plus vat plus delivery!

[Brit-Car-Nut]

The head gasket for turbo is A100E6104S and £29.76 + VAT and postage from ANY Lotus Dealer.

Usually, everyone buys the whole set from a place like Rock Auto and uses ALL of the gaskets EXCEPT the head gasket which they get from Lotus.

I believe I read that valve guide/stem seals are also a bit of a problem? I remember everyone running around to find the original design. I don't know if that is what comes in the other kits, but FelPro states their kit contains Premium valve stem seals. Other members tried to get the seals offered on Rock Auto by Beck Arnley but they are basically gone now.