Engine noise/rattle when starting up??

[ecswtrav]

Hi there, My 2000 2.7 Boxster has developed a strange sound whenever I startup the engine from cold. The sound also happens on occasion when the car has been warmed up. On starting the engine I get a grinding, maybe rattling type sound come from the back where the engine is - it doesnt stay on permanently, only for a few seconds and comes and goes. Initally I thought maybe the exhaust was loose but then when the car heats up the sound cannot be heard so ruled this out. The sound also has varying volume levels sometimes being rather loud. The sound will also be present on and off when driving until it warms up. The type of sound is difficult to describe and seems to be doing no harm. Its been present now for a few weeks - I was kinda hoping the cold mornings were at fault but im not so sure why this would happen and why it still happens on very mild mornings? Any help or suggestions would be gratefully appreciated as Im debating sending it to the garage and don't want to be conned into any expensive repair jobs when it may not be needed. Thanks

[Rick V]

Timing chain slapping? It isn't too commom but not unheard of

Originally Posted by ecswtrav

Hi there,

My 2000 2.7 Boxster has developed a strange sound whenever I startup the engine from cold. The sound also happens on occasion when the car has been warmed up.

On starting the engine I get a grinding, maybe rattling type sound come from the back where the engine is - it doesnt stay on permanently, only for a few seconds and comes and goes. Initally I thought maybe the exhaust was loose but then when the car heats up the sound cannot be heard so ruled this out. The sound also has varying volume levels sometimes being rather loud.

The sound will also be present on and off when driving until it warms up. The type of sound is difficult to describe and seems to be doing no harm. Its been present now for a few weeks - I was kinda hoping the cold mornings were at fault but im not so sure why this would happen and why it still happens on very mild mornings?

Any help or suggestions would be gratefully appreciated as Im debating sending it to the garage and don't want to be conned into any expensive repair jobs when it may not be needed.

Thanks

[kabel]

I was thinking valve tick... which is no big deal. I get that frequently on the morning starts regardless of the ambient temp. The valves clatter for about 5-10 seconds.

[pk2]

I got it to. Not always and for 5secs or less. All my better judgment said it was the lifters, still a little unnerving. You guy give me some peace of mind.

My experience with flat motors, lifters will drain there oil “cushion” out overnight. It takes a few seconds to get them pumped up again to where they behave like a shock absorber/tensioners for the valves.

Regards, PK

[ecswtrav]

If it is the valves clattering should the sound come and go? People who hear the thing start up in the cold think the cars in a bad way, including me - surely that can't be right? It really does make a racket which to me is not normal.

Can anything be done about this valve tick or chain slapping that isnt gonna cost a fortune. Thanks

[Padawan]

My 986 and my father's 996 are both rather noisy for a few seconds after initial start-up, and there is nothing wrong with either car. I believe the sounds you're referring to are perfectly normal. Out of curiosity though, what oil are you running?

[ecswtrav]

Padawan, but do your cars make this noise when warmed up and occasionally can be heard whilst driving - like a rattlesnake sound but how you would expect with metal parts rattling. Not sure about the oil it was replaced last June/July should I attempt to put some newer oil in?

[dcporsche99]

IMHO, it wouldn't hurt to change out the oil first using Mobil 1 (0W40)....9.25 quarts.

Keep us informed.

Good luck with that.

[Rick V]

good call. I had alot of lifter noise in my old 944. When re-did the head I made the cam followers too tight. The Mobile one cleared it right up. Might help here.

Originally Posted by dcporsche99

IMHO, it wouldn't hurt to change out the oil first using Mobil 1 (0W40)....9.5 quarts.

Keep us informed.

Good luck with that.

[ecswtrav]

Yep, I'll give the oil a change. May try it myself next weekend or ask the garage to do it this week - I need two new sidelights anyway. I'll keep you posted. Cheers

[Lil bastard]

I'm not sure taking your Wait & See approach was the best decision. Your engine is making noises where it previously did not - it's telling you something's not right.

These motors can cost upwards of $10k to replace, alot more than a couple hundred bucks for a qualified mechanic to look it over. And soon as possible, don't wait weeks before taking any action.

Seeking advice here isn't your best bet either. There are lots of knowledgeable people here, no doubt, but they haven't seen the car and have only your rather vague description to render a guess on.

It may be nothing, and I hope that's the case. But, if it turns out to be something, you're much better served by addressing it sooner rather than later.

My advice is to have it looked at and don't drive the car (or at least drive it very gently) until you do. Good Luck!

[ajrct]

Hi,

My S rattles until warm, sounds like a loose part in the exhaust but as soon as the engine is warm it goes away?? Also if revved gently the noise dissapears....getting worried now......

[mdex]

My catalytic converter sounded like that when it was on the way out... at a cold idle it rattled badly, but as it warmed up / or if it was under load there was no noise.... try banging on the cats when the car is cold (and off) and see if anything is rattling inside them.

[ajrct]

Thanks for the info..............I'll try that and let you know, cheers

[986Porsche986]

did you ever get this resolved? I too am noticing a weird banging startup
noise on my 2002 s. I was going to start a new thread asking for opinions on the sound in the video i am uploading.