Hey all, new to this forum but I just bought a 00 Disco with 174k miles to fix and sell on so I figured it was about time. Anyways, the engine makes a loud tapping noise 3-5 minutes after start up, sometimes longer. The noise will occasionally fade away and disappear for a bit, then come back. Once I saw exhaust shooting out from under the valve cover I figured it was time to do head gaskets anyhow so now that the valve covers are off what should I be looking for in terms of what could cause the noise?
Engine Tap and antifreeze + exhaust under valve covers
- Thread starter sholden7
- Start date
Slipped liner, bent valve or a rod bearing maybe? Could be anything really, time to open her up.
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And open she's a coming. I meant, say it was a slipped liner, what would be the best way to diagnose?riceybean said:
sholden7 said:
A big cylinder-sleeve shaped mark on the head gasket is a clue. A liner not at the same level than the others is also a good cluse (not always going to see that), and a block pressure test is a really good way to do it.
Unfortunately, there are plenty of blocks that pass a block pressure test but are still bad (some aren't bad enough to fail when cold). At best, a block pressure test is presumptive: if it fails you know it's bad. If it "passes" it doesn't necessarily mean it's good.
run to engine to normal operating temp, then do a cylinder leakdown test... a sliped liner will gurgle the coolant tank.... by the way you describe it you may have nothing but a leaking exhaust gasket..
Worn cam or clogged lifter will also give that noise.
If it is running OK and not losing coolant or pressurising, run some decent diesel detergent engine oil in it and see what happens. Ours had a tick which gradually cleared with time.
Peter
If it is running OK and not losing coolant or pressurising, run some decent diesel detergent engine oil in it and see what happens. Ours had a tick which gradually cleared with time.
Peter
It does have exhaust leaks but that's not what this is, and unfortunately I have already removed the IM and valve covers so i can't run it. I will continue taking it apart to the heads and see what's down there. The engine is horribly sludged, underneath Vcovers looks like someone splashed tar around.
That's how mine was when I got it, sludge all over and a year old date written on the oil filter. Might want to pull the lifters, clean them and soak'm good if everything checks out. I still have one that ticks after warm up.
If it is that sludged up, even more of a case for running detergent oil through.
Don't strip it down unless you need to.
Peter
Don't strip it down unless you need to.
Peter
I didn't really want to, but as I mentioned their was coolant under the valve covers which I don't believe should be there, so I figured I'd do head gaskets. I have a parts washer so before it goes back together everything will be given a thorough clean. This engine is absolutely filthy.
Well it's been awhile because of my other projects, but I finally managed to pull the driver's side head today. As I did, a fair amount of coolant spilled out. Is that normal? There were also large puddles on top of the cylinders but I'm thinking that's from what spilled out of the head. Once I get the other one off they will be visiting a machine shop.