Cayman 987.1 ticking

[Twinfan]

I'm definitely no expert, but don't the fuel injectors tick a lot on these engines? It might be that one or more are faulty or were damaged as part of the recent engine rebuild?

Might be worth checking those before dropping the engine again!

 

[Andywidmann]

Hi All. Kindly soliciting opinions. First, I know that 987s are ticky engines, and that there are lots of posts about ticking, but this ticking is new (and loud) and I haven't found any previous posts that seem to make sense for this.

This is a 987.1 Cayman s. It's has 70k miles. It had bore scoring, which was fixed by a Porsche independent shop here less than 100 miles ago (engine out, new liners, etc). The only place it's really been driven since the engine out is back from their shop. Shortly after I got the car back it started making a loud ticking noise. I've sent the below video to the shop, and they said it sounds like a bottom end bearing failure (but would have to check), but it would require a full engine rebuild and since it's not related to new liners they put in it wouldn't be under warranty. They suggested I don't drive car and tow it back to them. Needless to say two engine out services a few weeks apart is going to be financially troublesome.

Though I would check with you guys on the interwebs to see if anyone had any thoughts? Video to link below. The noise it the same if car is cold or warm. Obviously ticking increases frequency with engine rpm.

https://youtube.com/short...ex4-O2o?feature=share3

 

[Motorhead]

Hi Andy,

Apart from tappet noise, the Gen2 DFI engines do exhibit ticking noise from the fuel injectors, but that isn’t appropriate for your Gen1 engine. It could be a very noisy tappet, but really you need to get underneath the car as well as taking the engine cover off to get close-up to the engine and so get a better handle on the source of the noise.

Since the engine has very recently been out for repair, I’d definitely be going back to the shop to let them investigate the problem. They’ve had to dismantle the engine to carry out the bore repairs [heads off, crankcases out, new pistons, rings and gudgeon pins, or new piston rings at least], and it’s possible that something has gone amiss during assembly, so don’t let them fob you off with any excuses. With the engine stripped, I would expect a reputable garage to check the condition of the big end bearings as a matter of course.

Jeff

 

[Andywidmann]

Thanks Jeff, this is really helpful. I think the shop I took it to are good guys, but honestly a bit perturbed by the immediate response that it sounds like the engine needs to come our again and it wouldn't be under warranty from thier previous work.

I'm going to try to get under the car and get the engine cover off to try and determine where the noise is from. Might also see if I can get a local shop to diagnose before I have it towed to the original shop, which is over an hour away. Theyre also saying they wouldn't be able to get to it until late July or August at the earliest, so I guess there isn't much of a hurry to get it back up there.

 

[Motorhead]

Andy,

If they’re a well-respected Porsche Independent and are experienced with repairing bore scoring, I’m surprised that they’re not prepared to warranty their repair and rebuild?

Keep us posted on progress.

Jeff

 

[Andywidmann]

Thanks Jeff. Well, they said from watching the video they strongly suspect it is a bottom end failure which would require a full tear down and rebuild, but that isn't an area that they touched, and would only be a warranty job if it directly relates to the liners they renewed. Again, this is all a diagnosis from the video and obviously needs to be investigated to see what the issue actually is. I don't have enough technical knowledge to understand that IF it is a bottom end failure, if it could be related to the cylinder relining.

Again, thanks for the thoughts. Will post when I have someting figured out.

 

[BrianJ]

Seems amazingly coincidental. In the 20-odd years I’ve been on here and on boxa.net I don’t think I remember anyone talking about a bottom end bearing failure, but my memory may not be reliable. And 70k miles isn’t a lot.

 

[Motorhead]

Same here Brian, and I’ve been on here for more than 12-years, although that doesn’t mean that there haven’t been the occasional bearing failures of course. But the bottom ends of these cars seem to be robust in normal use.

In order to get to the crankcases the engine will have had to have been split into its component pieces [camboxes, cylinder heads, crankcases and main bearing carriers], which would leave the crankshaft, connecting rods and pistons/rings as a complete assembly, so I’m assuming that the repairer is maintaining that they haven’t touched the big end bearings? I assume that they’ve checked the condition of the main bearings, which would have been exposed, so I think it was very remiss of them not to have checked the big end bearings too while the engine was stripped. A no-brainer in my opinion.

Jeff

 

[BrianJ]

Having now listened to the video (sorry, not possible before) that sounds much more like a defective cam follower or valve than a bottom end. I have some history in that; my 986 knocked a hole in a cam follower on a bank holiday weekend in France when it was about 18 months old. Due to the absence of any recovery services I drove it 1000 miles home like that. The noise was more extreme than yours but of a very similar nature. In my case Porsche accepted responsibility with a known bad batch of poorly heat-treated cam followers; most of the head-related components were replaced. I can’t imagine that will be your issue but the noise certainly sounds camshaft/follower/valve related perhaps resulting from previous work. I wouldn’t describe it as ticking, which the hydraulic tappets can make temporarily before they fill with oil.

 

[BrianJ]

Another thought. Hartech presented on a club Zoom session a couple of years ago about bore scoring and associated problems, and their extensive research and solution. This session included issues they had seen from other suppliers repairs. You might look up that video for clues. I think it was Steve Johnson (now Register Director) who arranged the Hartech session. If you can’t find the video, it might be worth contacting him.

 

[AndrewCS]

In here or linked ?

hartech video - Google Search

 

[911hillclimber]

Obviously the engine did not have this noise before bore score work?

I would ask the indie to come to you (with trailer) to listen to the car.

Take it from there...

 

[Andywidmann]

Thanks so much Brian. Will check out the Hartech video. I'm away for work this week and wasn't able to get under the car before I left, but hopefully this weekend I get it up in the air and get the engine cover off to see if I can make any more sense of it.

 

[Andywidmann]

Nope, didn't have the noise before the bore scoring work. Basically, I drove it home from thier shop (about 50 miles). Thought I maybe heard a faint "ticking" or something then, but wasnt this. I had to take it back up to them a few weeks later as a bad cat was throwing an error code. On the way back home from that 2nd visit it got alot louder. Other than the trips back and forth to thier shop, I hadn't really drivien it, except maybe once or twice to the grocery store or something - since it was throwing a code for the cat I couldn't get the MOT updated and wasn't supposed to be driving it, so didn't really.

 

[AndrewT]

Could the noise be an exhaust gasket leak? Was the catalyst replaced, maybe the bolts/ studs are not fully tightened, or even broken?

 

[Andywidmann]

Well, I thought about that. I'm hoping/assuming not. I replaced the cat myself with a new (used) one myself after it came back from them the first time (I had to drive it back up to them to replace the O2 sensor that was stuck in the header). I torqued everything to spec, but was going to check again later this week. It doesn't sound like it is that, but if it is I'm a complete idiot.

 

[AndrewT]

As you replaced the cat yourself it’s probably ok but worth checking again anyway, I only suggested it because when I owned a TVR some owners experienced a ticking sound which was due to an exhaust manifold leak.

 

[Andywidmann]

Well, got under car and took engine cover off, but couldn't really pinpoint where the noise was coming from. Some videos below. Not great quality. Obviously has to go in to be diagnosed, but was hoping to get some clarity first. Think it might have to go into different shop from the shop that did the bore scoring to get diagnosed. Many thanks to everyone who has chimed in here so far.

https://youtu.be/mP3LuzJxmJ8

https://youtu.be/YJnRvXmfW9o

 

[AndrewCS]

Call - contact Contact Porsche Specialists - Hartech and see if they will accept - diagnose your recordings

 

[AndrewT]

An old trick to try and locate engine noises, if you don’t have a stethoscope, is to use a long screwdriver - put your ear to the handle end and touch the other end to various parts of the engine where you think the noise might be coming from. Admittedly this might be tricky in the confined space of a Cayman engine bay. Perhaps you could achieve the same effect with some small bore plastic tube?