So, i changed the Camshaft in my car after it started tapping and causing a light miss-fire.
Got it all back together last night and after running the cam in it still taps and settles to a slight mis-fire.
The Cam i removed was dead, over 2-3mm missing off some lobes.
I havn't had the rocker cover back off yet, but im thinking a dropped valve maybe?

 

Is it getting oil to the cam?

 

I have the same problem drove it a few miles now there is a terrible miss

 

Which cam did you go for in the end? (not that it really changes anything)
Whats your oil pressure? hot/cold
And i take it you ran it in properly?

 

Havn't tested oil pressure... I dont have a gauge!
Tried it with a new pattern cam and and good used cam from my collection. Both do the same.
It taps all the way through the 20minute run in and still taps now.
I'll pull the cam out tonight, inspect the head and check theres oil getting up there! Maybe run it without the rocker cover...

 

Another thing to note is that, ive recently changed to fuchs 10w50 oil, was using castrol 10w40 before. When i dropped the oil out after replacing the cam there was afew bits of "mayo" in it, leading me to think the head gasket has failed... But the cooling system doesnt lose pressure!

 

Clogged tappet???

 

Hope you fitted new lifters with the new cam. If not you've wasted your time anyway. Using a second hand cam was a waste of time IMO (with cvhs its just pointless).
Cant believe you haven't got an oil pressure gauge tho

 

I kept the original cam and lifters from an old efi engine, all labeled up. So no issue there!
The tapping was instant as soon as the engine started... So i think its something wrong with the valvetrain, valve stuck open etc?

 

When you say labelled up do you mean tappets in order too? If so thats fair enough.

Did you check over the rockers when you had it stripped. Ive had 2 (on seperate occassions) crack underneath that looked fine in situ, but when i removed them i spotted very fine cracks which under lift were expanding and causing a racket and essentially flex in the valvetrain.
Not alot else that can tick or cause misfires other than a burnt out valve tbh (compression test will soon show that one)

 

Had this once on a engine, oil wasn't getting to the cam.

Check the pressure but if it was me the head would be coming off

 

Harry i'll check the rockers, got afew spare sets so thats a good shout...
How will i tell if oil is getting up there without a gauge? Run it with the cover off?

 

It generally will tap all the way through the running in phase while its bedding in and the tappets fill with oil

Have you changed the oil after running it in? I hope so as all the swalf and metal filings will be running around your engine

When ever I have fitted a cam it's taken an oil change and a 20min run to get it to settle in

Check rockers are tightened correctly aswell

 

Disconnect power to fuel and spark and turn over with cover off and plugs out

You want it to pump into the head not just trickle

 

Yeah ive tried 2 different cams, properly run in. Its tapping the same as before, n giving a slight miss at idle...
I'll try cranking with plugs out tonight

 

Is it a loud tapping, almost like a knock or just a loud ticking sound

If its a loud tapping it would make me think that a lifter isn't getting any oil? But without seeing the car it's hard to see

 

So..
Cranked it over with rocker cover off n plugs out, lifters get soaked in oil within 2-3seconds and soon after the head has loads of oil round it.
Compression Tested her to, 138, 140, 140, 142. All 140psi near as makes no difference.
Checked the bores with a scope and nothing obvious... Some droplets in cylinder 1 around the head gasket, but not alot, could be excess fuel?
Maybe mis-fire could be a faulty coilpack and the tapping could be a lazy lifter or cracked rocker? Basically 2 seperate faults?

 

that misfire could be whats causing the excess fuel in one cyclinder?

i would take it for a slow run down a long carriage way and see if the tapping clears, my guess is the tapping will be on the same cyclinder as the misfire

 

tapping sounds like a lifter knackered tbh.surprised u haven't got an oil pressure gauge dude.my orion runs 80psi+ when cold and will stay around 60psi when at cruise

 

I'll put it back together today and run it up...

 

Got it all back together this morning and its fine now, good as gold...
When i removed a plug todo comp test last night it wasnt very tight, im wondering if that caused the tapping in the same way a blown exhaust manifold gasket does. Looking at it this morning it didnt have a compression washer on it. Would also answer to the misfire...
Plugs went in before the cam change was even thought of, and i didnt do much mileage on them before a tapping developed, plug working loose?
The mis-fire was still apparent on start up, but cleared with a quick blip of the throttle, lifter pumping up to take up the play in the worn cam?
So new cam solves the mis-fire...
But new plugs cause another one along with a tapping noise.

 

Hmm just keep an eye on it. If its sorted happy days, but we all know these engines like to fix themselves then break again several times per week

 

My advise is if it has fresh oil after the cam was run in, take it for a steady drive down a couple of junctions of motorways, it will help bed it in better and stop the tap on start up

Do this before giving it beans, it has always worked for me

 

Ive taken it for a nice long drive tonight... Cambelt tensioner has started rattling, its never fucking ends does it!?

 

time for a cambelt change, to be honest i change them and the tensioner everytime it comes off, might aswell put a water pump in at the same time and save the risk of having to do it twice

 

Now you've gone Efi, be easier to go zetec turbo lol...
At least it's a easy fix...

 

straight swap with some adaptor plates, bottom coolant hose, and drill the flywheel bolt holes slightly

 

A lose or ill fitting plug does indeed sound like the culprit, it would cause both problems, certainly with the compression washer missing! lol
At least a tensioner and belt are cheap and easy!

 

roger if you need a tensioner and water pump I have both that have done less than 1000 miles, cover the post and I will send them to you.