Chris Williams' Journal

I'll jump straight in:
Motor full rebuild 10k miles ago. I put it together myself .

Suddenly developed a motor rattle and I had it towed home. Checked compression, 1 & 2 virtually no compression. Further investigation established almost certainly a leak from 1 to 2. Oil clear. Water clear.

This was confirmed today after taking head off.






Everything else to do with the head looks ok. I'm a little worried about a bright spot on #1 inlet valve next to where the gasket failed.

And I can't see how this gasket failure can be anyway related to the sudden development of the motor rattle. I'm still thinking I'm going to have to go in deeper.

Bit more information, if it's relevant. I believe this break has been there for a little while. I'd noticed a drop in power over the last few weeks before the rattle. I put that down to it needing a tuneup.

This situation is not fresh the car's been sitting for about 2 months - under cover - with the rocker cover off and the plugs out. The bores feel good and I haven't taken the old gasket off the block yet.

I've also had a fluctuating vacuum gauge for some time and just lately noticed a fluctuating oil pressure as well.

I posted on the forum a few months - up to a year? - ago about some variation in compression figures but the consensus of opinion at that time was to forget about it.

One thing, if you look at one of the close ups of the blow through you can still see the machining ribs through the carbon going across the blow through area. I think it's safe to say that the head's ok at that point and there is no groove.
I'll have a closer look at the block after I take off the gasket and clean it up.
I still can't reconcile that the rattle is not something else so unless someone gives me good reason not to, I'm lifting the whole lot back out, putting it on an engine stand, flipping it, taking the pan off and checking everything down there to make sure that the rattle is not bearings, cam, or oil pump.
All of these were new or refurbished 10k ago.

Update! I have the cleanest mind around - that's because I change it all the time. I change it more often than I change my underpants!

New theory! Based on what all of the guys on the forum have said and closer examination of the head gasket after I chiselled it off.
(BTW this is what I made so that I could lay into the block without worry)



Anyway, I digress. After taking the h.gasket off I noticed a few things. (some of which the guys had already alluded to)

Contrary to what I'd surmised before, it does appear that the final failure of the gasket between 1 & 2 did occur at the same time as the rattle happening. There is evidence to suggest that there was/is leakage across the border 'tween 3 & 4 and even 2 & 3. You can see the section between 3 & 4 was close to failing also.



I also went back to my notes about the regular comp. tests that I had done and after tests at 600, 6000, 10000 and 10550 miles the results were all 'fine' in fact 1 & 2 had 150 and 160 at 10550miles. The mileage is now just under 12000 so I think it's safe to say that the piece blew out recently and most probably at the time of the 'rattle'.

I'm thinking that the 'rattle' was the sound of the compression blowing across between the two cylinders. I think the gasket was leaking long before that but the 'blow-out' is what I heard.

My mind is now thinking, clean everything up, new H.gasket, torque and run it/drive it. If no rattle all good - if the rattle still there, well then I go in.

I've ordered a h.gasket set, new studs and a few other bits and pieces from UK Moss and I'll put it back together and go from there.