Valley gasket

**Roverlord off road spares** · 16th February 2014, 08:33 PM

I took the top of the top off the D2 V8 today to fix an oil leak from the valley ends. It was some time ago I posted about a miss I had on the left bank. It was accompanied by popping and a sound like tin flexing, the pop would often happen after shutdown.
As you can see by the pic the valley has a nice dent in it. This would have been the popping sound I heard.
I can't see how the bad miss fire I previously had that has since been rectified could buckle the valley gasket.
Explosive combustion gases would either blow out the exhaust port or the inlet port. So unless they could get into the the engine block some how, I can't explain the buckling of the valley gasket. Even the possibility of them getting in under the valley gasket at the ports and exploding under the valley gasket to cause this damage

**PhilipA** · 16th February 2014, 08:51 PM

You probably have a head gasket leak from a cylinder into the valley.
This was more common with older V8s with the third row of bolts but may still happen.
Regards Philip A

**bee utey** · 16th February 2014, 09:08 PM

Isn't there a christmas tree thing in the breather that needs cleaning out regularly? A blocked breather will let blowby build up until it buckles the gasket. Worn out or broken rings or dusted/scored bores will do it too. Lots of old P76 engines used to get rags stuffed under the inlet manifold to keep the valley gasket down. Some with broken rings used to drum the gasket something shocking.

Also if you had a bad misfire a piston's rings aren't pushed against the bore and you'd get poor sealing and excess fumes. The ring faces get carboned up and leak more. Fixing the misfire and thrashing it would have rebedded the rings. I've seen engines with a busted plug oil up the cylinder quite alarmingly, a new plug and a thrash and all's good.

Brentttt · 16th February 2014, 09:15 PM

Cleaning out the little breathers in your rocker covers should stop this from happening again for a while and will also make it less prone to leaking.
Don't forget to check the hoses going from the rocker cover to the inlet as they can get quite gummed up too and are often forgotten about.

**POD** · 16th February 2014, 09:50 PM

Yep these engines pee oil out of the valley cover ends like there's no tomorrow if the crankcase ventilation is not kept clear, it appears that excessive crankcase pressure has bowed the valley cover, and it's popped like Rolf Harris's wobble board every time you have shut down. Brings back memories of trying to keep the engine oil inside the engine on these things for 18 years. Lots of grey goo on those valley end seals was the only thing that worked for me. Then the oil will find it's way out somewhere else if you let the breathers get gummed up.

**loanrangie** · 17th February 2014, 12:45 PM

Originally Posted by PhilipA

You probably have a head gasket leak from a cylinder into the valley.
This was more common with older V8s with the third row of bolts but may still happen.
Regards Philip A

I had this on an 81 3.5 rangie, took me a while to work out where the noise was coming from as it was a sort of tinny chuffing sound.

**camel_landy** · 18th February 2014, 02:45 AM

I'd go for a blocked breather...

M

**Pedro_The_Swift** · 18th February 2014, 05:10 AM

now would be a good time to change the leads!!

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