UKKid35

While working underneath the car removing the clutch I turned the engine approx two revolutions the wrong way, I was simply disorientated and got it wrong. I'm assuming there are several parts that could have been damaged:

Tensioner
Tensioner Arm Pivot
Cam Chain Tensioners

What is the real world likelihood that I have caused damage, and has anyone seen actual damage occur?

The only checks I can think of making are to ensure that the belt is tracking correctly and the belt tension is correct. Anything else I can do?

Maybach_Man

compression check???????????????????????????/

UKKid35

Hey Geoff - I think a compression check is a bit extreme, I'm not expecting anything to have gone that seriously wrong. I was just wondering whether tensioner damage was just a theoretical possibility, or something that had actually been observed.

WICruiser

When you have the belt cover off to check the belt tension turn the engine at least two full revolutions in the correct direction and look carefully at the timing belt as it comes into view for any evidence of damage to the teeth.

Leon Speed

And check camshaft timing - make sure the belt didn't skip a tooth (unlikely, but better safe than sorry).

SeanR

Agreed. run the belt around several times so you can visually check the track and tenstion before start up. If all looks good, then start it up with fingers crossed.

Garth S

Hi Paul,
Another vote for carefully turning the crank clockwise to verify the TB timing marks. IMHO, there is no way that the tensioner could have been harmed, and I would be astonished if the TB had an pre-adolescent teething issue .... Having said that, it is always a good idea to reverify the correct tension, as you are already there.

Were there any concern about reverse direction rotation ( on a 32v motor), it may be regarding skipping a tooth on the cam-cam chain drive whilst their tensioners are flat: following the TB verification steps, it cannot harm to pull the FP relay for the first spin on the starter so as to build tensioner oil pressure> If you hear no 'clanks' start up & enjoy

Some of these steps are precautionary as is whistling to keep elephants away - who knows, but I've never seen an elephant around here yet ...

borland

Remove the valve covers and check the plastic cam chain tensioner guides for damage.

UKKid35

I agree there is a theoretical possibility of chain guide damage, but has that ever happened to anyone?

I'm far too lazy to pull the cam covers just to be sure they're ok, unless someone tells me they've seen chain guide damage due to turning anti-clockwise.

928ntslow

I have done this many times with no adverse effects. I don't think I ever went 2 revolutions, but know I have turned it backwards at different intervals on different cars, 16v and 32v. As stated, I think the only thing that could get affected is the belt skipping a tooth if the belt is loose enough. Nothing else matters which way it goes as long as it doesn't "run" that way YMMV

UKKid35

Thanks Keith, very reassuring.

bsztanko

None,

done it a 100 times no probles.

PorKen

(WSM)

(15-15) Never turn engine anticlockwise, since this could destroy the camshaft drive belt tensioner.

(15-18d) Never turn engine anticlockwise, since drive belt could jump out if its tightness is insufficient.

(15-104) Never turn engine anticlockwise, because toothed belt could jump off if tightness were insufficient.

PorKen

Where does the 1500 mile new belt recheck interval come from, BTW?

I only see one reference in the WSM, for 1000 KM (600 miles)!

(15-14) Make sure new drive belts are retightened after driving approx. 1,000 km.

Mike Frye

I panicked about the same thing when I was doing my clutch. The general reaction was that it wasn't a good idea, but should be OK. Some said that as long as you do it in small increments it shouldn't be a problem. The biggest concern was for the cam chain tensioners, but it turned out there were no noticeable effects on mine.