Engine Rattle - bottom end fail?

[SurlySurdi]

OK, to bring you up to date with developments, I thought I had an issue with my fuel pressure regulator and I had it replaced yesterday, however there is still a problem.

The engine revs up ok but coming down from 4000 rpm plus there is a noise like a bag of.spanners. my mechanic turned the engine off and said to me it sounds like the bottom end has gone.

Now, he may think that but I need to be sure and so the question I have is that what should I do now to figure out what's happening inside the engine? Thanks.

SS

[Beaky]

If he's right Don't drive it!

I'm no expert so just thinking aloud

Our cars have a very mechanical sound to them but not a bag of spanners and if that was never there before something is a miss.

Is the sound deep and from the bottom of the engine as opposed to rattily from from the cam area?

You could drop the oil see if there are any metal fragments in it, do a bore score check, check the cam chains, etc.  but frankly the only way is to get a second opinion from another reputable Porsche Indie - may need to be trailered there or pay them to come inspect.

If 2 say the same thing then the engine will needs to be striped to see the level of damage and estimate for a full rebuild..

What the mileage, has the engine ever had a rebuild? 

[SurlySurdi]

Had a top end done 6 years ago. Mileage is 121,000 now. My garage looks after all my cars so not a porsche specialist but for most things they are OK. However,  for this I think I need a specialist as you say. I was toying with the idea of driving to a garage I know who are specialists but sounds like that's a bad idea! I'll need to find a low loader in north Kent. I'm trying not to speculate what has happened too much, it leads down to some expensive avenues!

SS

[PeterK]

Just to put an alternative option - what about a broken clutch rattling ?

[Phill]

Bag of spanners seems like timing chain(s) to me. Shall we start a guess the issue competition?

[PeterK]

Wouldn’t tensioners rattle at tickover though ?

[Chris T]

I’ll go tensioners. Ok revving up but rattles on down. The hydraulic tensioners on a 3.2 are a notorious failure but easy to replace. Were they changed at 121,000 miles? Many cars get up to starship enterprise mileages before bottom end needs replacing…. Try putting a long metal rod like a long screwdriver to your ear and then on various bits of the engine as you rev it. See if it most prevalent around the chain housings. 

[Chris_911]

Bottom end gone would be a severe knocking.

Is it a light or heavy noise?

chris's advice above is spot-on!

[Nige]

Straps on the exhaust snapped or come loose.

[Ian Comerford]

I wouldn’t risk running it again but would, arrange to transport it to a Porsche air-cooled specialist with a good reputation for diagnosis.

[gt two]

I had a metallic noise that I pinned down to One of the heat exchangers having lost a weld and making a rattling noise. Could be one of a few things.

Get Jevvy to visit, he travels to Kent and also will be cheaper than getting a trailer and then a specialist.

Edited October 6, 2024 by gt two

[Nige]

10 minutes ago, gt two said:

I had a metallic noise that I pinned down to One of the heat exchangers having lost a weld.

Get Jevvy to visit, he travels to Kent and also will be cheaper than getting a trailer and then a specialist.

Exactly, why I mentioned the straps on the exhaust.  Loose tinware, mufflers, heat exchangers, etc vibrate like hell and sound terminal.  Fine under load but make a massive racket whilst the revs fall.

Mine had snapped exhaust strap on the way back from Goodwood a few years ago, sounded fine under load, but as soon as you come off the throttle it sounded like valves, chains, pistons where all smashing together.

If its not this, worst it could be, I imagine is a failed chain tensioner. Hopefully.

Bottom end, top end whatever is all gradual, you would have heard that slowly develop over time.

 

But yes, get it to a specialist.

 

Edited October 6, 2024 by Nige

[PeterK]

If needed I have spare pair of (used) hydrauluc tensioners on the shelf in my ‘just in case pile’

[SurlySurdi]

Thanks for everyone's response, I will get it diagnosed by a specialist.

Is a compression test recommeded? In fact do we have a list of symptoms and possible causes to refer to? 

Thanks.

SS

[Beaky]

7 hours ago, gt two said:

Get Jevvy to visit, he travels to Kent and also will be cheaper than getting a trailer and then a specialist.

This would be my first point of call,

[Phill]

2 hours ago, Beaky said:

This would be my first point of call,

+1

[SurlySurdi]

Regarding Jevvy, would someone DM me his details please? Thanks.

SS

[tea boy]

15 hours ago, SurlySurdi said:

Regarding Jevvy, would someone DM me his details please? Thanks.

SS

Search for jevvygee on instagram 

[SurlySurdi]

I had a porsche mechanic come over to diagnose my engine issue. He inspected the engine, ran it and tested for the noise. Above 4000 rpm when coming off the throttle the noise is apparent. 

The advice I got was to talk to an air cooled engine specialist. I was told that it would be difficult to diagnose without opening the engine up. I'm beginning to understand the variability in costs for engine rebuild, it comes down to how bad the damage is.

He did say he suspected the small end might be involved.

SS

Edited October 7, 2024 by SurlySurdi

[Nige]

we was hoping for something simple, still more checks required though before ripping into it.

Edited October 8, 2024 by Nige

[Phill]

13 hours ago, SurlySurdi said:

I had a porsche mechanic come over to diagnose my engine issue. He inspected the engine, ran it and tested for the noise. Above 4000 rpm when coming off the throttle the noise is apparent. 

The advice I got was to talk to an air cooled engine specialist. I was told that it would be difficult to diagnose without opening the engine up. I'm beginning to understand the variability in costs for engine rebuild, it comes down to how bad the damage is.

He did say he suspected the small end might be involved.

SS

Some Porsche mechanic 

[Type911]

Obviously a water cooled Porsche Mechanic

[SurlySurdi]

3 hours ago, Type911 said:

Obviously a water cooled Porsche Mechanic

It's funny, I did ask him that. He responded by stating that after rebuilding one 10 years ago he promised never to do another!

I'm wondering if I should have the engine removed and shipped to be rebuilt?

SS

[Nige]

"Small end being involved" seems a bit random and I've never heard of anyone else having wear there to the extent that you can hear it.  I consider it pretty rare for something like that to happen without prior warning/slowly degrading.

There is a whole bunch of pretty low level stuff on these that can cause a right racket, slipped rocker arm shaft, loose exhaust, etc and all the above suggestions.

What mileage does it have?  It's usually valve guides on 3.2s that start going first.

 

Edited October 8, 2024 by Nige

[SurlySurdi]

3 hours ago, Type911 said:

Obviously a water cooled Porsche Mechanic

It's funny, I did ask him that. He responded by stating that after rebuilding one 10 years ago he promised never to do another!

I'm wondering if I should have the engine removed and shipped to be rebuilt? Assuming that whoever opens the engine for diagnosis and also ends up doing the rebuild, Who do you guys recommend for a diagnosis/rebuild?

10 minutes ago, Nige said:

"Small end being involved" seems a bit random and I've never heard of anyone else having wear there to the extent that you can hear it.  I consider it pretty rare for something like that to happen without prior warning/slowly degrading.

There is a whole bunch of pretty low level stuff on these that can cause a right racket, slipped rocker arm shaft, loose exhaust, etc and all the above suggestions.

What mileage does it have?  It's usually valve guides on 3.2s that start going first.

 

121,000 miles, top end rebuild about 15,000 miles (6 years) ago. I'm just finding this whole thing very unusual since the top end rebuild was not too long ago. This is stressing me out big time!

 

SS