So my car has been parked in my garage for the winter. I did the usual precautions including an oil change before parking. Battery maintainer all winter. The garage temperature is moderated only getting slightly below freezing during this long and cold winter.
On the weekend I started it up, it fired up right away and settled into a regular idle after a few minutes. That's when I noticed a bit of a knocking sound coming from the right side of the engine. The sound rises and falls with the revs. It is not overly loud but I can definitely hear some kind of knocking. The car was running perfectly when it was parked for the winter. I know diagnosis by internet is virtually impossible but does anyone have any thoughts on what this could be? Of course I am thinking the worst, spun bearing or something like that. Oil pressure gauge reads good pressure. I let the car idle for about 5-6 minutes, the sound did not go away, I shut it down and have not run it since.Thoughts?

 

I'm no expert on these things, but I've heard that a Durametric can be of assistance in diagnosing these types of situations.

 

Definitely get codes read before any guessing.

Just my opinion, but starting the car to just let it idle for 5-10 minutes is really not good practice. It actually might do more damage in the long run...cold starts after the oil has settled is the most damaging. If you are going to start it occasionally at least run it long enough to burn off any accumulated moisture from condensation and get the oil up to temperature...

 

Lifters that were collapsed will knock until they fully pump up.

 

I would say go for a drive to really get the car warmed up, with the stereo off so you can hear what your engine is doing. I bet the sound goes away once it's been warmed up and driven a bit.

 

Lifters would be my guess as well. I've had several 'summer' car experience similiar attributes, if there are no codes, drive it around to raise till normal operating temp, and see if the sound goes away.

 

I completely understand that. I do not start the car up during the winter at all. This was to be the start up of the season so it was the first time I was firing the car up. Upon letting the car warm up and the knocking not going away I shut it down. Normally I would have taken it for a drive but hearing this noise for the first time after winter storage I am hesitant to drive it until I can investigate further.

 

I appreciate the feedback. I was thinking lifters might be a possibility as well. The weather here is going to cool off again so I'll wait a week or so when it warms up again and take it for a drive to get it to full operating temperature and see what happens. Fingers crossed!

 

+1 for lifters, something to try which might help: about a hour before the next drive/fire-up, remove the fuel pump relay and crank engine until oil pressure is built up, this might help bleed/pump the lifters in time for the drive.
Otherwise, if still noisy on fire-up, avoid high-rpm running until quiet
Cheers,

 

Thank-you for the suggestion!

 

Actually, running the motor at a moderately high rpm, say <4000 will increase oil flow and help the lifters fully pump up quicker. The rattling of lifters is not hurting the motor at all. Lifters that become too tight and hold the valve off the seat or keep them from closing fully can cause damage. Lifters that are too tight are totally quiet. Another very misunderstood fact. I deal in this daily and have for decades:-)

 

I respectfully disagree based on my findings and knowledge, but to each his own. Cam lobes seem to be most effected with 'flat' lifters, have also seen more lifter bore scuffing due to 'hammering'...also not necessarily looking for increased oil flow, but rather to bleed the air out. There's a reason we prime lifters....
Stuck valve/lifter will definitely cause the most direct damage but that's not truly related to the OP's issue.
Again just my take on the subject.
Cheers,

 

OP you haven't started the car in months, what do you expect? Get the car running for a bit and I'm sure it'll be back to normal in no time.

 

Fair comment but this is the first time I have ever experienced this. Typically after its winter sleep it fires up like it did but then settles into a nice normal idle. I have to admit I was rattled (pardon the pun) when I heard a new noise. The feedback is reassuring as it appears I am over-reacting to what may be fairly common.

 

What you have in all likely hood is a lifter going bad. I had the exact same symptoms a few years back. Did a thread on it here:

https://www.6speedonline.com/forums/...ve-lifter.html

I had all 24 lifters replaced with the 997 versions. About $3500 parts/labor.