Head gasket

Submitted: Saturday, Oct 03, 2015 at 12:48

ThreadID: 130497 Views:3038 Replies:4 FollowUps:7

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Nick D3

Just was wondering what might be wrong. I've put the new head on my 1hz motor and the gasket is leaking oil out on the drivers side of the head. The pasanger side is fine. I tightened the head bolts in the correct order and procedure I'm shore so not shore why it is leaking. Any ideas and ways to fix thanks.

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Reply By: Life Member TourBoy, Bundaberg - Saturday, Oct 03, 2015 at 13:47

Reply By: Member - Barnray (NSW) - Saturday, Oct 03, 2015 at 19:06

Reply By: Ron N - Saturday, Oct 03, 2015 at 19:09

Saturday, Oct 03, 2015 at 19:09

Nick, did you ensure the gasket was correctly positioned as regards the right way up?
Some gaskets can be installed wrong way up (front and rear reversed) and look correct, but the oil and water holes do not line up correctly.
Did you check carefully to see if all the oil and water holes in the gasket, were in line with the ones in the block?

Did you check the top of the block with a straight edge and feeler gauge to see if it was warped or buckled?
The tolerance for warpage or buckling is around .004" or 0.1mm for most engines.
Any variation more than this amount will generally ensure the gasket doesn't seal properly.
If the engine has been overheated, the block may be warped.

Did you read the manufacturers gasket installation instructions? Some manufacturers have very exact procedures to follow.
Did you use any type of gasket cement or silicone sealant?
Some manufacturers will allow gasket cement to be used, some state that no gasket cement must be used under any circumstances.

Cheers, Ron.

AnswerID: 591123

Follow Up By: Nick D3 - Sunday, Oct 04, 2015 at 09:30

Sunday, Oct 04, 2015 at 09:30

Hi there. Yer I'm shore the gasket went on the correct way. When I took the old head off the old gasket had no trace of any glue being and the new one had no instructions to use glue so I didn't put any with it. The head was replaced because the engine was overheated and cracked the head. I inspected the one I replaced it with and it seemed fine I didn't put a straight edge over anything. The motor runs fine so would that mean the block couldn't be warped.

FollowupID: 859198

Follow Up By: Ron N - Sunday, Oct 04, 2015 at 11:15

Sunday, Oct 04, 2015 at 11:15

Nick, an engine can run just fine with a warped block. But if the head-to-block gap specifications are outside manufacturers limits, you will get compression, oil or water leaks.
If the engine has been overheated, it is crucial that you check all the manufacturers specifications before you re-assemble the engine.
One of those crucial specifications is checking for block warpage.

A block can develop some amazing buckles when overheated or overstressed.
It can develop misalignment in the bearing tunnels - so that's why it's critical to ensure the crankshaft spins freely when all the bearing caps are snugged up, and before any further assembly is done.

Many people fail to check all the manufacturers specifications upon overhaul.
One that is regularly missed is flywheel runout. There is always a specification for flywheel runout, and if the flywheel runout is outside specs, then you are likely to have unacceptable vibration, a possible bent crankshaft flange, or a buckled flywheel (flywheels get hot from slipping clutches and can buckle).

Cheers, Ron.

FollowupID: 859204

Follow Up By: Nick D3 - Sunday, Oct 04, 2015 at 21:01

Sunday, Oct 04, 2015 at 21:01

Hay mate. Ok so it would be worth my while pulling the head off and running a straight edge over it. Unfortunately it's starting to sound like the block is bugged. I was hoping that it was only the gasket but being brand new and I did bye it off ebay as a cheeper option then local stuff but it shouldn't be leaking oil it's not much but it's leaking it more I think when you put your foot down or it's at high revs.

FollowupID: 859236

Follow Up By: Ron N - Sunday, Oct 04, 2015 at 21:32

Sunday, Oct 04, 2015 at 21:32

Nick, if you want to stop the leak, and it's leaking excessively, you don't have much choice but to pull the head off again. And yes, the block needs to be checked for warping.
I trust the gasket you bought was a reputable brand, and not a "Chinese special" with dubious quality.
Yes, the oil leak will increase with higher RPM, because the oil pressure increases with higher RPM.
If the block is warped, it doesn't mean it's buggered - the top will need to be surface ground on a surface grinding machine.
Surface grinding means the engine has to be totally dismantled, as it's not possible to surface grind the block with components installed, as the grinding dust will penetrate into them, and destroy the engine after it is re-assembled.

Cheers, Ron.

FollowupID: 859238

Follow Up By: Stu & "Bob" - Monday, Oct 05, 2015 at 10:58

Monday, Oct 05, 2015 at 10:58

If you are going to pull it to bits to surface grind the block, you might as well chuck in a piston and liner kit while you are there....

Get the head checked for warping as well...you just never know.......

FollowupID: 859252