Mark-87-951

I changed my cam tower to head gasket today and now even though the engine runs smooth and has power there is this popcorn sound. The normal engine sound pretty much drowns it out a 3,000+ rpm.

So what could this be? Did I trash my car?

hoffman912

i wouldnt run it til you have it checked out. better to be safe than sorry. does it sound like exhaust popping or internals mettal crunching popping etc?

Mark-87-951

Sounds like its coming from the engine compartment. I didnt have any choice but to drive it home which is less then 5 minutes.

hosrom_951

When you took off the cam, did any of the hyrolic tappet fall out?

Chris_924s

I was wondering the same thing.. maybe something loose or foreign fell into the cam tower?

Mark-87-951

all the lifters are in. I replaced 4 because i wasnt thinking when I ordered - duh moment to say the least.

Mark-87-951

well I did have a bolt fall in as I was removing it but I fished that out. Maybe the washer got left in. I can check easily enough tomorrow.

hosrom_951

When you replaced those 4 new ones, did you soak them in oil for a while BEFORE you installed them?

The manual states that if the tappets fall, them you should mark which one goes where and soak them in oil for a while before installing them. I guess that applies to new ones as well.

Mark-87-951

agh -- No I did not soak them. They didnt fall out so the old ones are in the same location as before. Would they be noisy this long?

Strike-Force

Is there a bag of popcorn under your hood you don't know about? Be careful, if it pops and gets larger and presses against your hood it may damage your paint!

hosrom_951

Mark: the manual states that you soak tappets once they are removed, otherwise it would take longer for them to get lubricated (or something like that).

How long have they been noisy now?


The popcorn wouldn't damage the paint if he used butter

Mark-87-951

Just this evening I ran it at idle perhaps 10 - 15 minutes total while checking different things and then starting itup again. I dont get the sound when i disconnect the coil and it just cranks. Im not sure if that is relevant though. I then drove not even 5 minutes home/

Danno

Check the plugs. When you pulled the cam-tower, some of the spark-plug wires may have gotten damaged, leading to one cylinder running lean and detonating.

Mark-87-951

hmm - well that would explain no noise when just cranking right? I will check that. I was going to change the wires anyway. Problem is it was late and I was so tired that as I tried to put the beru connector on the kingsbourne set I pulled the screw end off the wire - dang it.

hacker-pschorr

I like Danno's idea - the timing was off by about 30 degrees on my Scirocco when we bought it (it's actually a common mistake on these cars - stupid timing markers) - under almost any load, it sounded like a sh*t load of popcorn popping it was detonating so bad.