REBUILD: 1st ADVICE REQUEST - CHAIN TENSIONERS

[goldgunner]

Just begun the long block tear-down:
1980 911SC 3.0 Bought in May 2005; 188K Miles

And, on this engine - serial # 6402151 - I was surprised to find that I have the Carrera hydraulic chain tensioners.

> Any chance this was 'original'? Or, must this have been a tensioner replacement ('upgrade') at some point?

The real question at this point - Totally leaving aside the debate and question about whether the mechanical or hydraulic tensioners are superior/more reliable:

> Considering that I'm performing a very total and complete rebuild, should these existing Carrera hydraulic chain tensioners be replaced with new ones?

> What wear factor on these type chain tensioners should be considered?

> I haven't seen any potential for 'rebuilding' this type tensioner - is that correct?

All experienced perspectives and advice is gratefully appreciated!

Thanks!
Jim

[89red911]

I would say go ahead and replace them. They arent that expensive and at least you will know that they are new. Its a piece of mind thing. If your alread in the motor that far your taking them off anyway.

[ChrisBennet]

I donno. I've gotten brand new tensioners that were bad (wouldn't pump up). I wonder if the old ones were better quality than the new ones?
-Chris

[sammyg2]

If you have carrera style hydraulic tensioners in your engine, they are an upgrade and not original.
Based on the problems with infant mortality the carrera tensioners have reportedly had (as reported on this board in fact) i would absolutely not mess with them if it was my engine but others will disagree. New unproven is not as good as used and proven IMO. Way too many people here and on rennlist have had problems with new or nearly new carrera tensioners collapsing.

[Jeff Alton]

I agree with both Chris and sammyg2. If they are working now, don't screw with them. If they start to fail at some point down the road, they are easy to change with the motor still in the car.

Cheers, Jeff

[89red911]

im a firm beliver in preventing headachs down the road if your there why not just replace them with what ever you choose.

this is just my thinking maybe right maybe wrong

i would change them

[ChrisBennet]

Originally posted by 89red911
im a firm beliver in preventing headachs down the road if your there why not just replace them with what ever you choose.

this is just my thinking maybe right maybe wrong

i would change them

I would normally agree with you. It's just that I'm not sure if the new tensioners are better than the old ones they'd be replacing. I could go either way on this also.
-Chris

[BReyes]

Yes, upgraded tensioners. I would reuse them if within spec. They didn't fail. You can look at them for evidence of wear. And they dont need to be rebuilt. If they fail, they are replaced.

Regards,

[89red911]

i agree with checking them to be sure they are in spec and if they are to reuse them. but as BReyes said if they fail replace them. i guess i look at as if im already there and its not going to taker any more time to do it then why not it could and i stress could save you time later.

but once again this is just my thoughts i think you have a strong argument either way

[Bobboloo]

"If it ain't broke..."

[Porscheologist]

I replaced the original tensioners in my SC with Carrera tensioners several years ago and drove the car for several years with no issues. I have read that the real culprit is the chain guides that are made out of plastic and eventually break(I replaced them as well). I would leave the Carrera tensioners alone and replace the guides if they look worn.

Just my 2cents.

[nilknarf]

Jim- you may want to do a search for "JWE Spacers" for your hydraulic tensioners- I think it'd go a long way towards easing your mind about re-using your current setup by preventing your hydraulic tensioners from total colapse in the event of failure- they kind of work like the old collars, but they're actually more like slugs that go inside the body of the tensioner from what I understand.

_curt

[goldgunner]

I've read several threads that make reference to "JWE spacers", but none that give - to me - sufficient information as to configuration, sizes, and installation.

Anyone have specifics or sourcing on these spacers?

Thanks!
jim

[nilknarf]

I remember seeing a thread on this late last spring, but after searching for a bit I couldn't find the threads... I remember that Wayne was one of the significant contributors to that conversation...

Wayne?

_curt

[Rex Walter]

Here is a thread on the chain tensioners with the Jerry Woods modification

Shops that don't recommend Carrera Tensioner Update?

Rex

[nilknarf]

oops- my bad! After reading the engine rebuild book cover-to-cover, I must have it fixed in my mind that Wayne has ALL the answers! My apologies for mis-appropriating the credit, but yes- that's the thread I remember seeing. Thanks Rex- now I can bookmark that page for when I get around to my rebuild!

_curt