engine knocking/tapping?

[DumpdDirTEEDubZ]

Have a 95 Vr. Just did mk4 headgasket, car ran fine have about 450 miles and goto start and motor is knocking/tapping fairly loud. Swapped ecu to check if chipped(giac) ecu was adjusting timing to far. Still knocking so swapped back and wouldn't start with either ecu plugged in. Pulled intake Mani/valve cover and spark plugs everything looks good no noticeable bent valves or damage to pistons. Checked oil and no metal pieces. Im completely lost. Chains are new looking with good tension.... any advice or ideas what could be problem?

[Scotty_2.0]

What all was done exactly? Did you replace the lifters? And if not, how long was the engine down/apart for? I suspect it's just the lifters being full of air. When I went to start my engine after the rebuild, it was knocking/tapping very loudly but slowly began to quite down and eventually went away as the lifters bled themselves and filled completely with oil.

Air in the liftes does little to dampen the noise, it's the oil inside that acts like a shock absorber and keeps them quite.

[DumpdDirTEEDubZ]

Head was off for maybe hr to clean inspect etc. But just to replace headgasket because it was leaking below by freeze out plug. Ran decent except for low idle which I suspect is dirty isv. I drove the car for 450 miles without a problem went to start other morning to warm up my normal 5-10 mins and right when I went to turn over it started and was making the noise. Not sure if crank or knock sensors could have failed n causing this? Im fairly new to the vr6 game.

[mk4vrjtta]

sounds like lifters...is it coming from the top of the motor or the bottom?

[CasuallyWreckless]

so now it wont start at all? ill be out there sun ill have a look hooker!

[DumpdDirTEEDubZ]

K davey.... but its hard to tell if its from top or bottom. I finially got my phone back from verizon damn thiefs... n ill post link to video.

[Nuzzi]

where are people getting there info these days
why would you think the ecu has anything to do with lifter noise? dumb question but are you low on oil? what weight are you running? you most likely caused another issue by messing with the ecu, its probably not seated correctly or if you swapped em with the battery connected it may be toast. also even though i cant understand why people dont soak new lifters after 450 miles it wouldnt make a difference. and there is no way to visually see a bent valve by just taking the intake/ valve cover off....

[DumpdDirTEEDubZ]

Disconnected battery ecu is in correctly. I ran 10w30 full synthetic. Same as my other vr. Well visually u cant by just looking at them but i have a little camera that use to insert into motor etc. Dip stick shows oil is good n looks fresh. Motor almost sounded like it was missing at same time as knocking sound. About to drain oil and see if a bearing spun or pump screen is clogged.

[JonLott]

What did you find? I am having a similar issue. My motor ran fine for around 300 miles. Then mine did the same thing as yours.....any information would be greatly appreciated!!!!

['dubber]

Check plugs and wires for failed parts/loose connection or maybe you can isolate an area of concern based on plug condition or if you see fuel on top of one of the slugs or something. You might think about getting it running again if you think it won't hurt it and use a mechanics stethoscope to isolate the noise before taking it apart any more. Those things are cheap and really work well. You can listen to individual things rotating and moving around in there, and it's surprising how moving it just a little bit can really change what you hear. It will probably help out a lot because a lot of times bottom end noise sounds like it's coming from the head when you are just standing there, or you have a trans noise that sounds like it's coming from the block, etc.

[JonLott]

Well, did a compresstion test yesterday....here are the numbers

1 140psi
2 160psi
3 140psi
4 140psi
5 125psi << Noisey area
6 140psi

So, I live in Germany, a good VW mechanic and friend of mine who has a VRT in his MK2. Said he thinks it's the lifters. So he is gonna bring me a set to try this Saturday. I will also ask him if he has any extra wires. May as well try it. When it runs, it doesn't sound like it is running on five cylinders. It idles smooth and revs smooth, just has an awful tapping. Thanks for the response. Everything helps, I hadn't thought about the wires. They were pulled of my old motor and work fine there......Thanks again!!

[JonLott]

Check plugs and wires for failed parts/loose connection or maybe you can isolate an area of concern based on plug condition or if you see fuel on top of one of the slugs or something. You might think about getting it running again if you think it won't hurt it and use a mechanics stethoscope to isolate the noise before taking it apart any more. Those things are cheap and really work well. You can listen to individual things rotating and moving around in there, and it's surprising how moving it just a little bit can really change what you hear. It will probably help out a lot because a lot of times bottom end noise sounds like it's coming from the head when you are just standing there, or you have a trans noise that sounds like it's coming from the block, etc.

When I ran the compression test, I did it with the motor cold. Didn't want to warm it up in fear of damaging anything. I cranked it over 5-7 times and only pulled one plug at a time. Everytime I pulled another plug, it had fuel on it. They are all fresh plugs and all still looked fresh. Only other thing I can think of is wires, but they are getting spark from pack to wires and out the other side.....S

[CasuallyWreckless]

His car jumped a tooth and bent a valve running fine other than a bad valve stem seal

[JonLott]

His car jumped a tooth and bent a valve running fine other than a bad valve stem seal

This is what I am starting to think is wrong with mine.....guess I will find out tomorrow!

[CasuallyWreckless]

His tensioner was shot and broke... We ended up pulling one of a spare head at our shopand putting it in... Shoulda poped a new seal in as well I think it tweaked it when it bent the valve but it's his daily and was just a quick fix

['dubber]

Did it really skip a tooth or did it just lash up on decel?

[tomslik]

Did it really skip a tooth or did it just lash up on decel?

That's a great question. Well , did it actually jump a tooth?