knock disappears when engine is hot?!

[sonicnofadz]

I've noticed lately that whenever my engine gets to its operating temperature (around the middle on the stock coolant gauge) my engine pulls 10x harder and my logger shows almost no knock whatsoever. When I just start my engine, (keep in mind its like around 30-40 F outside) I'll get 43 counts of knock just accelerating (with no boost only vaccuum) in any gear. Is there a reason for this, or is this a common phenomenon? I've noticed that my coolant light keeps flashing on and off depending on the engine rpm, so I think my water pump might be a little worn (bearings may be causing phantom knock). Any ideas?

 

[TSIfreek]

The lifters are bleading down all the way when you shut the car off for the night and is what is causing your knock untill oil gets flowing in the head real good and fills them back up . I would replace the lifters with updated ones that cures this problem. Should be ok after that. Also try adiffrent oil filter. Some filters have poor anti drain valves in them causing all of the oil in the filter to drain out when the car is shut down.

 

[carbonfire]

I have the same problem... hahha.. I think it is normal... but how hard is it to change lifters? I might want to do that real soon

 

[sonicnofadz]

I have revised lifters. However I just recently switched to a bosch oil filter...wonder if that has anything to do with it? I also have an oil leak somewhere...that probably doesn't help keep things primed either =)

 

[TSIfreek]

I have revised lifters. However I just recently switched to a bosch oil filter...wonder if that has anything to do with it? I also have an oil leak somewhere...that probably doesn't help keep things primed either =)

What oil are you using?? Is the oil clean??

 

[sonicnofadz]

I'm starting to think that I may have damaged some of the lifters...they are new revised lifters but they were taken from a head that had bent valves (timing belt slipped). So I think maybe a couple of them are defective and are causing some weird knock. I heard some WEIRD clicking noises coming from the valve cover area, and it later on disappears when the car is warmed up. Maybe one of them (or a couple) aren't holding the oil like they are supposed to (they aren't staying pressurized). The oil is pretty clean. I just changed to a bosch oil filter, and I have a pretty nasty oil leak near the timing belt side of the engine (the belt isn't soaked). So I dump half a quart of low grade mobil 1 10w30 (non synthetic) every time I drive. I'm going to have the timing belt off soon for the water pump replacement so I'll take the valve cover off just to see if any lifters are visably damaged.