Hi,
Whilst under my ZX at the weekend to change the exhaust, I located the source of my slight oil consumption, a nice slick under the exhaust manifold i.e. new HG required.
My question is, which gasket to use? My engine (ZX TD) has 107k on the clock and has had a fairly hard life to date, so I am expecting to fit a new engine in about 12/18 months time. To provide the most appropriate fix now would a metal or fibre jobbie be best?
Thanks,
MTMN
Head Gasket
Moderator: RichardW
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oilyspanner
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Always get it skimmed, always use the metal gasket(Thick one for skimmed head) always use new bolts, are you sure its the head gasket? the rocker cover gasket is prone to leakage and the oil we always find in the intercooler will get into the inlet manifold and may dribble down the back of the block too, some of the engines I see look like an oil well on the back of the block for years without trouble.
Stewart
Stewart
As the cylinder head face is flat skimming it will have no effect on the compression ratio ( other than a very small ammount due to the valves being slightly deeper in the bore, if the valves have also been lapped in probably not even a slight increase in compression). The compression ratio in these engines is important ( it could cause difficult cold starting amongst other things). The gasket thickness should be determined by measuring the piston protrusion using a dial test indicator and use the greatest protrusion to determine the gasket thickness.
0.54 to 0.65mm protrusion 1 notch
0.65 to 0.77mm protrusion 2 notches
0.77 to 0.0.82 protrusion 3 notches
I think there is a four notch gasket but this is only fitted by the factory.
0.54 to 0.65mm protrusion 1 notch
0.65 to 0.77mm protrusion 2 notches
0.77 to 0.0.82 protrusion 3 notches
I think there is a four notch gasket but this is only fitted by the factory.
I'm in line with Stewart -
Get the engine cleaned externally thoroughly before you decide for any repair.
As soon as weather stays above 0'C - drain & flush the cooling system - then fill up using half & half water & winegar. This will clean out any calcium in the HG coolant thru holes - which are known to block after y's & miles of service.
Run the car with this mix for 3-5 weeks - then flush the cooling system - removing the rad for reverse & forward flushing several times.
Get the engine cleaned externally thoroughly before you decide for any repair.
As soon as weather stays above 0'C - drain & flush the cooling system - then fill up using half & half water & winegar. This will clean out any calcium in the HG coolant thru holes - which are known to block after y's & miles of service.
Run the car with this mix for 3-5 weeks - then flush the cooling system - removing the rad for reverse & forward flushing several times.
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Dave Burns
- Posts: 1915
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- x 2
The pressurised oil feed to the head is on the other side (front), the oil return drains are at each end of the head, it is therefore extremely unlikely that the oil is getting out from the head gasket on the back side.
Water passes between the head and block very close to the edge along the heads length, any problem with the gasket most of the time will be that of water containment, water will usually get out before oil does, oil rarely gets out from the gasket in any quantity at places other than the pressurised junction between the block and head.
The worst oil leak I have had on any of my cars was on my old ZX td, this leak was from the camshaft oil seal, it ran down the front of the head and along the head/block union making it look like the head gasket had failed, my knowledge of the head told me the gasket would not be the culprit.
A new oil seal and all was well again, this engine is now in its third car having covered about 154k it started life out in a Xantia and is now in another ZX, and still on the original head gasket.
Dave
Water passes between the head and block very close to the edge along the heads length, any problem with the gasket most of the time will be that of water containment, water will usually get out before oil does, oil rarely gets out from the gasket in any quantity at places other than the pressurised junction between the block and head.
The worst oil leak I have had on any of my cars was on my old ZX td, this leak was from the camshaft oil seal, it ran down the front of the head and along the head/block union making it look like the head gasket had failed, my knowledge of the head told me the gasket would not be the culprit.
A new oil seal and all was well again, this engine is now in its third car having covered about 154k it started life out in a Xantia and is now in another ZX, and still on the original head gasket.
Dave
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Jon
Dave
Point taken here, but when I got my ZX (cheap!!!) at 70k, there was a major oil leak at the back of the head, so bad that the the oil was burning off on the turbo. I did the usual steam clean, then rocker cover and O/S camseal. It was still leaking down the back of the block, big style.
I then "whipped" the head off, there was a slight trace of contamination of the h/gasket at the back of the head between 2 and 3, nothing that looked bad. Bear in mind this car was water tight too.
As I was in a bit of a rush (borrowing Louis Barbour's workshop on a Saturday) I cleaned everything up, and fitted a (traditional) type Meillor head gasket, 3 notch, with new head bolts, and torqued down. I have to say that was 2.5 years and 62,000 mile ago and it has not leaked since. [:p]
Obviolsly the best plan is a steam clean, and maybe run the car at tickover with the intercooler off to confirm if its the camseal first off
Point taken here, but when I got my ZX (cheap!!!) at 70k, there was a major oil leak at the back of the head, so bad that the the oil was burning off on the turbo. I did the usual steam clean, then rocker cover and O/S camseal. It was still leaking down the back of the block, big style.
I then "whipped" the head off, there was a slight trace of contamination of the h/gasket at the back of the head between 2 and 3, nothing that looked bad. Bear in mind this car was water tight too.
As I was in a bit of a rush (borrowing Louis Barbour's workshop on a Saturday) I cleaned everything up, and fitted a (traditional) type Meillor head gasket, 3 notch, with new head bolts, and torqued down. I have to say that was 2.5 years and 62,000 mile ago and it has not leaked since. [:p]
Obviolsly the best plan is a steam clean, and maybe run the car at tickover with the intercooler off to confirm if its the camseal first off
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MountainMan
- Posts: 26
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- Location: United Kingdom
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Thanks for the help,
From looking at the back of my block, I think Jon's on a winner, the rocker cover gasket was changed 6 months ago and the leak pattern orginates from mid block so unlikely to be any cam seals (oil smoke appears from under the car when accelerating, so assume leak is burning off on the turbo also).
I'll be steam cleaning at the weekend, to confirm.
Could someone point me in the direction of the correct Andy Spares HG (assuming thats the fault), I won't be getting any skimmming done as the engine is simply not worth it, just want another years life out of it.
Thanks again.
MTMN
From looking at the back of my block, I think Jon's on a winner, the rocker cover gasket was changed 6 months ago and the leak pattern orginates from mid block so unlikely to be any cam seals (oil smoke appears from under the car when accelerating, so assume leak is burning off on the turbo also).
I'll be steam cleaning at the weekend, to confirm.
Could someone point me in the direction of the correct Andy Spares HG (assuming thats the fault), I won't be getting any skimmming done as the engine is simply not worth it, just want another years life out of it.
Thanks again.
MTMN
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Dave Burns
- Posts: 1915
- Joined: 14 May 2001, 05:30
- Location: United Kingdom
- My Cars:
- x 2
Hmmm...thats a tough one Jon, there are no oilways at that location, there are only three oilways all of which are at the ends of the head, one pressure oilway at the front left corner and two oil drains at the very ends of the head, these don't contain pressure and the oil just drains from the head back to the sump.
If oil could make its way to the centre of the block from one end and under the gasket, how could it even think about hanging on to the water, which is all over the place along the gasket, got me beat with that one, a cracked head could explain it I suppose but what a crack it would be[:0]
Dave
If oil could make its way to the centre of the block from one end and under the gasket, how could it even think about hanging on to the water, which is all over the place along the gasket, got me beat with that one, a cracked head could explain it I suppose but what a crack it would be[:0]
Dave
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Jon
Good point Dave, how the oil got there I don't know, but believe me it was running down the back, and getting on to the manifold and turbo.
Changing the H/G certainly solved the problem!!! As I mentioned above though, rocker cover gasketand camseal came first!!!!
Also had a similar problem many years ago on the old Visa D, unexplainable oil leak in the head area. Had the head off that too.
Maybe I just love changing head gaskets!! ?
Changing the H/G certainly solved the problem!!! As I mentioned above though, rocker cover gasketand camseal came first!!!!
Also had a similar problem many years ago on the old Visa D, unexplainable oil leak in the head area. Had the head off that too.
Maybe I just love changing head gaskets!! ?