CharlieBravo

My car has a noticeable tick in the morning at cold start. If I do nothing it will continue ticking. If I rev to 1500 for 15-20 seconds then the tick is gone/diminished. Coming mostly form drivers side. Once warmed up, no longer there or noticeable.

Car has just under 62k miles. IMS replaced 20k miles ago. Otherwise drives very well.


I just changed oil to 0w40 (was 15w50), had water pump and serpentine belt replaced along with bank 1 side chain tensioner. Oil filter was clean.

any thoughts?

jobyt

Drop the sump plate and borescope the cylinders for evidence of scoring. There's a numerous threads on this forum that you can find for tips and advice.

Mike Murphy

My 99 has been doing this for 4 years, from 48k miles to 66k miles. It’s probably early onset bore scoring, or IMS tensioner, chain tensioners.

My advice is to keep the revs up. Don’t let it idle. I think Porsche didn’t design cold starts on this engine to make sure enough lubrication is occurring, and it’s much worse in colder climates.

I know others with cold start noise like this as well; this is not rare on the early cars.

Mike Murphy

Also, check out the FSI video on ‘living with bore scoring,’ as early onset could be considered ‘normal’ bore wear and could last a long time before it get bad. There are a couple of recommendations in there that might help.

Lastly, keep tabs on your cam timing, as you may need to do the other bank tensioner pads. If one side is worn, and if they are original early tensioner pads, then the other side is probably going to need to be done (top and bottom) at some point. Note: the top on one side will wear the same way the bottom of the other side wears, so it’s not always easy to see the wear with a visual inspection.

I had all 4 tensioner pads replaced and my car still rattles at cold start.

CharlieBravo

i have read numerous posts about the topic. I guess the difference in this situation is that with low range revving for less than 30 seconds resolves the sounds. Initially was leaning toward tensioner and oil pressure related for that reasons. Would scoring issues demonstrate that symptomatilogy?

Mike Murphy

It certainly could be tensioners and pads, but the only way to know for sure is to bore scope it.

I took a video and sent to Jake at FSI. He said probably early onset. He said to look at the dark coloring on the header by the head. But to be sure, have the engine scoped top and bottom. I already had 2 cylinders scoped last year at a Porsche expert, and he saw ‘expected wear for this engine and mileage,’ but I trust Jake’s comments over 1,000 miles than I do my Porsche mechanic.

CharlieBravo

Error. Delete

twitchett

My car made this exact noise and had the exact same symptoms (noise went away by first stop sign down the street).

I am convinced a bunch of early cars make this sound and none of the threads for the '99s that make this sound end with a solution. I feel like everyone lives with it or sells.

For what it's worth, mine probably did this since I bought it, but I didn't clue in on it until fall of 2016. It ran that way at least from fall 2016 to fall 2019, which is when I took it off the road to have an engine rebuild. In 2017 I had the sump dropped and the bores scoped. They looked fine. I also had it done in July 2016 when it was purchased. When the engine was disassembled in May 2020, early onset scoring consistent with age & mileage (76K miles) was discovered. Engine internals were otherwise clean and the engine did run strong. My car didn't really consume oil and I didn't see any in the exhaust, either.

I would recommend watching for more serious symptoms and otherwise drive it and don't let it sit upon cold start. I still pull away shortly after starting and I keep revs around 2K rpm for a few minutes, and then I shift at 3K rpm until it is up to operating temperatures. Maybe someone has a different opinion, but if it is anything like my car (or Mike's), this process seems to work just fine.

Mike Murphy

That’s what I’ve been doing for 4 years and it hasn’t gotten any worse. Like you, I don’t have much oil consumption. Maybe I won’t be tracking the car to 7,300 RPM with oil starvation like I did before, but I went from “oh no, this is terrible,” to “this is not a huge problem right now,” and will probably sign up for a Stage II FSI in 1-3 years, since the car runs great for now.

I think the noise is actually metal to metal contact. Maybe the bores don’t get hammered as bad on the 3.4 engine as they do on 3.6 or 3.8 engines, or maybe the metal to metal contact is the chain slapping against the tensioner rails, but if the noise can be erased with RPMs due to increased oil pressure, or oil jets onto the cylinder bores, then that’s fine with me, I feel like I’m doing the right thing to avoid some wear.

If it weren’t for cold starts, I’m convinced these cars would run for 300,000 miles.

CharlieBravo

Anything different about the 99 engine compared to other .1 models?

I find it very unusual that it’s not a persistent tick. Like I said a little rev for about 15 seconds the it’s gone when back to idle.

I don’t think it’s related to oil viscosity.

Mike Murphy

Agree with this.

Woodman71

My '99 makes a similar sound when it hasn't been started for a few days. The tick is a bit slower than this, but same tone/volume.

Porschetech3

Sounds like the catalytic converter to me. Get a Mechanics Stethoscope and get under the car while cold and have some one else start the car and listen to the cats.....

I have seen a lot of knocking and ticking from cats that you would swear was internal engine noise, goes away above idle and only does it cold/hot .................

twitchett

It is interesting that you mention this. I may have to look into this for myself. I always categorized the sound as more of a rattle/vibration that easily outpaced the rpm of the engine. I have also had an issue with mufflers developing a rattle, which I thought was a failing baffle and caused me to replace the mufflers. I just assumed OEM mufflers are getting older and this is to be expected. The rattle in the mufflers always developed after hard spirited driving. Perhaps the internals of the cats are breaking down.

I think I may have to check on the condition of my cats..

CharlieBravo

not sure it’s the cats. I tried to brace the cats with my hands on start up today, no changes noted.