Pop goes the something or other

[campbellju]

My wife helped me tow the car back this morning. My mate dropped off my compression tester so I've just been out testing.

From cold, cylinders 1,2,3 were 150s, cylinder 4 was 130

The inlet pipework was all clean which doesn't rule the turbo out but makes it less likely.

The engine has run fine so I thought I'd get it warm to check.

150's across all 4 cylinders now

Got my torch into the cylinders and 1,2,3 are all black but a little wet looking. Number 4 is clean as if its brand new.

Did it again but now I had all the plugs out and noticed a puff of something from cylinder 4 everytime the car turned over.

My thinking is its more water than oil. I checked the oil cap and this time there was a thin milky film on the cap.

The head or crank case does seem to be breathing excessively either way.

I just broke the bad news to the wife that the car might not be dead and I might have to spend the weekend taking the head off.

So far it all points to a HG or cracked head.

 

[red reading]

I think its the block surface has distorted.

 

[Thor]

when your compression is on all 4 cylinders are not too big difference than it is normally ok. If the head is cracked you have much lower compression!

 

[pulsarboby]

have you compression tested it with all plugs removed jim, if not then try that to see how much readings vary
also drop a spoonfull of oil down no 4 plughole to see if compression comes up

could possibly be a cracked head as sascha has said, you wont be able to confirm anything untill the heads removed

 

[PobodY]

What head gasket is it; is there a chance it's blown-out? I appreciate that the chances of that might be quite small, but that's better than a cracked head.

 

[campbellju]

Thanks everyone, I appreciate the comments.

Danny, another interesting idea.

Sasha, hopefully not but if Danny is right it might still end up in the bin.

Bob, yep, got all the hot compressions to 150s, it was only the cold compression that was out.

George, its an HKS metal head gasket. I've not heard of them failing but there is always a first.

As people have said, I need to whizz the head off to check but its helpful to think what it might be before I start.

All the best,
Jim

 

[red reading]

I have a reason why it may be the block and part of it is to do with hks gasket's and the aluminum block deck as the cylinder liners do not go to the top of the block.it will be interesting to see what jims car has done. jim tech forum?

 

[campbellju]

I'll certainly try to bribe Stu to come up once the head is off as he has more experience than most with leaky heads. I've booked in some garage time with the wife tomorrow so I'll see where I get to. It might be blindly obvious once you can get at it and have a proper look.

Will keep all forums informed if its anything interesting. A failed piston or HG isn't very exciting nowadays :lol:

 

[R called Jay]

Hi Jim,

Aren't you being a little eager taking the head off if all compressions are ok?

Ben.

 

[campbellju]

Fair comment Ben. There is definitely a problem with water in cylinder 4 but the quick and dirty fix might be some ceramic sealer instead. If that is the professional fix I might give it a go. I know Stu tried something similar. For quick and dirty also read, might last long enough to get me to JTS! The RAC could get me back

 

[red reading]

Hi Jim,

Aren't you being a little eager taking the head off if all compressions are ok?

Ben.

not really ben as all other checks have not given the answer to the fault,so the only option now is to wip it's swede off and have a look inside;-)

 

[stumo]

Hmmmmmm

the clean cylinder can indicate water getting in there and effectively steam cleaning it.

It might be worth taking the plugs out again and holding a clean cloth over the plug hole and see what comes out.....it could be oil or water and you'll see it on the cloth!

The fact that the cylinder pressures are the same (when hot) just indicates the the comp rings are ok, it could be the oil ring that's gone.

If the HG is gone or the head cracked then i would have thought the water temps would be high!

Assuming it's oil....If the inlet tract/pipework is oil free then it's not the inlet side of the turbo. If the ex manifold is clean and downpipe is oily then it's the ex side of the turbo.

Jim, it might be worth borrowing the sniffer to see if there's combustion gasses in the coolant, give me a ring.

I still wouldn't rule out stem seals........

 

[R called Jay]

How about pressure testing each cylinder, such as a leak down test.

If you put pressure in cyl 4 with rad cap off then you should be able to diagnose without taking anything off.

Or the other way is to use a coolant system tester, which sits where the rad cap is and you pump pressure into the coolan system. If the pressure drops over a set time you can see that there's a problem and also mght be able to see where the coolant is escaping from.

I'm a real great believer in a thorough diagnosis can/will save a lot of time/money in the long run.

 

[red reading]

How about pressure testing each cylinder, such as a leak down test.

If you put pressure in cyl 4 with rad cap off then you should be able to diagnose without taking anything off.

Or the other way is to use a coolant system tester, which sits where the rad cap is and you pump pressure into the coolan system. If the pressure drops over a set time you can see that there's a problem and also mght be able to see where the coolant is escaping from.

I'm a real great believer in a thorough diagnosis can/will save a lot of time/money in the long run.

me too

 

[R called Jay]

Stu, whats a sniffer?

 

[campbellju]

Thanks Stu. I've sent you a text. I think its 90% water out the exhaust and cylinder 4.

I'm going to make a start now stripping easy stuff off around the head.

Speak to you soon,
Jim

 

[red reading]

checks for the pressence or not of comustion gasses in the engine coolent

 

[campbellju]

Fair comments on the sniffer but cylinder 4 looks like a steam train puffing out a fine mist every every compression stroke. I might be able to better diagnose it with a few more tests but apart from ceramic sealing it (feels like a bodge) I don't know how I'd fix that. I have a spare standard HG on the shelf if I want to lash it back together again.

 

[red reading]

I have a spare cosworth gasket,used for 250 miles still like new

 

[red reading]

You can have it if you need it