carrera chain tensioner - how easy to compress?

[Chuck.H]

Checking up on a new rattling noise, thought it was the alternator but removing the belt didn't change the noise, so I opened the cam covers. On the left side the tensioner is very tight, cannot move it at all by hand. The right side (where the noise was) is not loose, but I can reach in there and compress the tensioner with hand pressure only... is that normal or too easily compressed???



I also don't like the amount of chain stretch on the right side -- the tensioner rod is farther out of the barrel by about 5mm more than on the left side, but I guess it's to be expected at this mileage...

Thanks in advance,
Chuck.H
'89 TurboLookTarga, 336k miles

[gamin]

Don't believe you should be able to compress with your finger. Usually takes a vice to compress.
I had the rattle in my 88. Could compress with finger. Replaced both tensioners. Can be done without full engine drop, with difficulty.

[Jesse16]

I remember the ones on my 87 being very tight, no hand pressure movement.

[Chuck.H]

Thanks for the replies - I'm leaning towards replacing the chains also since they seem to be stretched a bit.

Has anybody replaced just their timing cam chains and NOT replaced the sprockets?

Chuck.H
'89 TurboLookTarga, 336k miles

[Grady Clay]

Chuck.H,

Please post good images of your sprockets.
The condition of the sprockets (idler & cam) will have an indication of chain wear and condition of the sprockets on the jackshaft.

Seldom is it wise to replace these ‘outer’ parts without replacing the jackshaft sprockets.
Inspection is the key.
If in doubt, leave it alone. These are very long-lived parts.

Best,
Grady

EDIT,
The reason for finding serious distress in this area are failed chain ramps.
Too often a failed tensioner and a broken chain ramp causes a cam to ‘jump time’.
Inspect the inside of the chain housings for signs of the chain previously ‘jumping over’ the sprocket.
Every time you have access to this, replace the chain ramps with new.

[Chuck.H]

Hi Grady -

Sorry I don't have a better pic than the one posted, but you can see how far the piston needed to extend in order to take up slack in the chain (way more than the right side). Also you can kinda see how close the idler gear is to the case at the 3:00 mark, and how close the chain is on top of the idler gear is to the ramp.

I think at this point I'll put in a new tensioner and plan a top end rebuild in the next year or so at which point I'll address the chains and sprockets.

Chuck.H
'89 TurboLookTarga, 336k miles

[snbush67]

I think that maybe why you are able to compress the tensioner by hand is because the oil fed lines are not connected and pressurized.

The picture you posted is not clear but is the tensioner missing the ball and cage (nipple)?

[KTL]

Originally Posted by snbush67

The picture you posted is not clear but is the tensioner missing the ball and cage (nipple)?

That's a very good question. When the ball & cage (pressure relief mechanism) are missing, the tensioner doesn't hold pressure on it's own.

I agree that a Carrera tensioner should not be able to be compressed by hand. Even "empty" Carrera tensioners that are new out-of-the-box are near impossible to compress by hand. You have to use a pair of big pliers, C-clamp, bench vise, etc. to pump the piston.

[Chuck.H]

Thanks for all the responses!

I was short on time, so I didn't get a visual on whether the ball and cage were in place. I did feel where it should be and it felt like it was in place but I had to leave on business and didn't get a chance to get a mirror or wrangle around to view it. I did notice that when I compressed it, no oil came out of the weep hole like it did on the firm left tensioner, which could indicate the check valve was missing.

Chuck.H
'89 TurboLookTarga, 336k miles