whitefox

I had my timing belt warning light come on, so following Tony's timing belt write up I attempted to find the problem.

With a lake of coolant on my garage floor I measured the timing belt tension with the Kempf tool, which I attempted to fix with turning the tensioner adjustment bolt clockwise. The tension of the belt does not change, I turn the motor over several times and take another reading, same tension.

If I do not take the reading at TDC my tension is perfect, at TDC I get a loose tension reading.

blau928

1/ Where did your lake of coolant come from...?

2/ When was the last time you changed the TB/WP?

3/ Have you checked the tensioner wires to see that they are not grounded/touching something?

4/ The coolant lake if caused by dripping from the front of the motor, tells me that maybe the WP failed, and you have a loose belt because of it.... (I just replaced a faulty WP and did the TB and tensioner rebuild as well.....)

HTH,

whitefox

The lake of coolant came from me trying to get away with not draining the radiator, and losing just a bit of coolant. Well that didn't work, live and learn I guess.

TB/WP was changed by PO about 4000 miles ago. PO retensioned TB at the 1500 mile mark after change.

I can't seem to get the belt to tighten up at all.

heinrich

Get a fellow rennlister there stat.

blau928

Have you checked the tensioner...? If you are at full thread in on the bolt, then something's odd.. The belt is at tension point with lots of room. Did the PO rebuild the tensioner when they changed the TB/WP..?

You still didn't say why you were draining the rad...? I'll guess it was in reference to another problem, as you do not need to disconnect the rad to tension the TB....


Does the engine make funny sounds when you turn it over? (BY HAND I AM GUESSING AT THIS POINT..?)

Sab

tensioner tool will only read correct at TDC. The belt shows different tension when not at TDC.
Turning the tensioner a full turn will show a change in t-belt tension.

Jim R.

If you are tightening the tensioner bolt and the belt is not snugging up un the gauge, I would look at the tensioner arm pivot bolt for signs of bending or loosening. If the belt is that loose 3500 miles after a retension, something is losing grip, not simple belt stretch. Time to take it apart if that is the case and be happy you have avoided disaster. Could be a bad water pump, roller, tensioner arm bolt, loose cam/oil gear. Find the source-the tension gauge does not lie (you did lube the pivot point on the Kemph tool right).


Do not start the car until you find out why!


Jim

jeff jackson

do you remember wher the tensioning bolt was before you made any adjustment ??? Is this the first time you've ever had the "toothed belt tension" warning come on ?? I'd set it back where it was...and start over. Was the engine "cold" when you got the warning?? If yes...probably need to add oil to the tensioner. If no...investigate cause of the warning by pulling the belt covers....and inspect all contact parts...rollers tensioner etc. If everything is intact, follow the well documented guidelines, and retension your TB. Did the PO do the water pump at the same time the new belt was installed ???Pretty important, at this point...

Steve J.

Is the coolant lake manmade or is the water pump leaking? How is the tensioner boot condition, t-belt condition and tensioner oil fill? Something strange here. Proceed cautiously grasshopper. There is much wisdom in the group. Better to learn from other people's mistakes. Good luck!

Big Dave

As others have said, belt tension MUST only be measured with the crank at TDC. With each adjustment of the tensioner, you must crank the engine 360 degress back to TDC (which means all the way around so that the cam gear timing marks are also lined up again with the crank's TDC).

Even a cold engine should be able to be tesioned properly with ample room remaining on the tensioner bolt. If you're bottoming out on the bolt and still not getting the correct tension, SOMETHING is loose...or the tensioner was not rebuilt properly. The tensioner contains a series of angled washers that alternate in direction. If those washers were set up all facing the same direction, they can lead to the symptom you're describiing...it could make the overall length of the tensioner too short (or too long in the other direction).

But before you pull the tensioner apart, inspect the entire path of the timing belt and make sure that everything is aligned properly. Gears can be seen to wobble if they're mounted on a bent arm, which could result in alternating tensions...and could also be the source of your fluctuating tension at various points in the belt's travel.

I'll assume that the coolant is the result of your pulling off a hose before draining and nothing else. If, however, you have coolant leaking while the whole system is still closed, you'll need to find the source. The first suspect would be the water pump since you already have belt tension issues.

My belt failed about 18 months ago, and I traced the problem to a bent tensioner arm bolt. It's a $13 part that failed causing much more $$$$ in damage. I'm pretty sure that the bolt bent because the belt was overtightened...and the bolt ended up being the weakest link and the first component to give way to the extra tension.

Good luck!

ErnestSw

Are you measuring the bottom or the top of the loop? The proper measurement is taken from the bottom loop.

Garth S

-The S4 has the much more robust tensioner pivot stud vs the M8 threaded bolt on all MY to '86.5 inclusive, so bending is not impossible, but less of a concern.
-I'm sure the coolant is from removal of the top two hoses on the right - this creates much more working room, and well worth the 4-5 min to do so.
- Were the tensioner washer stack misassembled, there would have been an issue at time of installation - not months later: There is a 4mm deep well in the bottom piston with the check valve that receives the top piston rod shaft containing the belville washers. In the worst case, this rod would bottom out the last ~2mm without washer contact, leaving a solid steel column from the tensioner bolt to the pivot arm - even so, there's still lots of adjustment travel left in the bolt to compensate for that.

With the lock nut released, ~ how much has the adjuster bolt been turned inwards ( clockwise)? If close to operating tension previously, 1/2 turn can make a very noticible swing on the gauge. Pardon the question, but were the measures taken at true TDC - with the cam timing marks set on the cover index points? From there, each retest must be two turns clockwise of the crank to restore true TDC. On a cold engine, oil is not needed to be added to the tensioner until final tension is set - but then, it need be topped up.
Yes - as mystified as you why there is not instant gratification when turning in the tensioner adjustment: if it was done at true TDC on a belt that had only been turned clockwise up to - and not past the marks ... then pull the covers for a closer look.

whitefox

The coolant lake is from removing the hoses without draining the radiator.

All tensioner adjustments have been taken at TDC, I only took measurements on spots other than TDC for curiosity.

I only have a few threads left on the tensioner bolt with NO change in belt tension, I am procrastinating digging deeper, I just wish it was as simple as adjusting the tensioner bolt correctly.

I am going to fetch some food and continue my quest to get her back on the road.

heinrich

Is someone else in Sarasota able to go help?

whitefox

Well I have found the problem, I am embarassed but regardless I found out why it wasn't adjusting.

The good news is the Power Steering pump belt is tight
I'm not worthy

Thanks everyone for your input.