Replaced valley gasket and now running like bag of spanners

Hi,
Ive just replaced my valley gasket with a composite one as the tin one i installed previously started leaking coolant (some bolts which i had torqued correctly had come loose).

When i start her now she sounds like a bag of spanners. The engine vibrates visibly and she hunts.

Also when i took her for a drive she seemed underpowered. When getting up to about 60 she seems fine.

Any ideas chaps?

I dont think i have a vacuum leak as everything was torqued and sealant was used on all mating faces.

Thanks.

Did you put the plug leads on correctly?

Spark Plugs? didnt move em, or do you mean the lead 4 the injectors?

Im going to check the injector plugs at the weekend (im not driving her at the mo) to make sure i put them in the right order, i should have done as i put labels on everything! Hmmmm

waterdude said:

Spark Plugs? didnt move em, or do you mean the lead 4 the injectors?

Im going to check the injector plugs at the weekend (im not driving her at the mo) to make sure i put them in the right order, i should have done as i put labels on everything! Hmmmm

Click to expand...

could be a number of things, if youve replaced the valley gasket you would have had to unplug alot of main componentsas stated before make sure the the injector plugs are connected the right way around, there is also an idle air control valve which may have not been plugged back in, and also a thottle pot sensor which can make it run realy ruff... i think your just going to have to go over everything again to make sure you didnt forget anything or maybe nocked a HT lead off..... if youve got a vacuum gauge that will be a good test to do, make sure it reading about 40in-hg you never know your piston rings maybe well warn and there maybe a leak past the valley gasket, but IMHO i wouldnt say it was that, as you would hear a loud sucking hiss to make an engine run realy badly...is it bad on tickover or just reving it, and does it sound like a missing cylinder or just bad runningsome times a quick test to do if its missing is to unplug 1 injector at a time to see if it makes it worse, if it dosent on 1 cylinder then you know your problem lies there, then you can test spark plug, ht leads, coil packs, compression test, injectorlet us know how you get on regards adam

Thanks Adam, will let you know how i get on. Hopefully just a injector wire crossed or maybe injector wire broken.

So was about to tear down the top half of the engine and got to step 3

Step one. Depressurise fuel rail
Step two. Disconnect battery
Step three. Unplug and remove MAF

Only MAF was not plugged in. :mil89:

Bang head against bumper a few times. Plug relays back in. Reconnect battery. Start er up................BINGO running like a creamy dream, funny that eh?

Surprised she ran at all without maf plugged in.

Please feel free to flame!

Ho-Ho-Ho

waterdude said:

Hi,
Ive just replaced my valley gasket with a composite one as the tin one i installed previously started leaking coolant (some bolts which i had torqued correctly had come loose).
When i start her now she sounds like a bag of spanners. The engine vibrates visibly and she hunts.
Also when i took her for a drive she seemed underpowered. When getting up to about 60 she seems fine.
Any ideas chaps?
I dont think i have a vacuum leak as everything was torqued and sealant was used on all mating faces.
Thanks.

Click to expand...

Something to add. If possible never use composite valley gaskets. The rubber on the underside goes brittle and quite large parts can and do drop off and can block the oil pick up pipe. Got this from ( http://rangeroverworld.blogspot.com/ ). To check up on this I removed a composite valley gasket from a 3.9 V8 I will be rebuilding and had a look on the underside and yes it was breaking up with brittle chunks already dropped into the sump. No more composites for me. The 3.5 tin type is the way to go. Glad you got a fix and she is running smooth.