Right guys,

Not having much luck lately. Went to a local specialist to get the water pump changed. Anyway he did it.................Put it all back together again. Started the engine and it started to make a kind of screeching noise from the front. He put some grease on the belt because he told me the coolant was on the belt, hence the noise.

Anyway on my way home i see smoke coming from the left hand side of the bonnett. Pulled over...Looked inside, nothing obvious apart from a burning rubber like smell.

Then i hear a kncking type noise coming from the front of the engine. Well the front/passenger side.

Took it back and he thinks the little shock absorber at the front and/or the belt tensioner pulley is at fault?

Any thoughts on this guys. The engine is rattling but the noise goes away on high rpm.

Many thanks!

what model and mileage?

I'm wondering if the grease on the belt caused the burning smelling rubber.

belt tensioners can go bad and squeal.

Sorry Ethan its a 190E 2.5-16...Year is 1990

Can this kind of thing damage the engine in anyway?

Yes im paranoid!

Yes, the little shock absorber for the belt tensioner can make an irritating rattle. When I replaced mine it was due to the bushing on the alternator side being worn out and too much play. Replaced the shock and no noise.

But, I would also take a hard look at the belt tensioner to make sure it is functioning properly and not defective. These things happen sometimes when they are loosened and re-tightened. The rubber bushing goes bad and tears.

Hey Zak, did you ever find out what was causing you full throttle problem?

Dave

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Hi Dave,

Many thanks for the reply as always :-)
Have not had a chance to figure that one out yet!

Forgive my ignorance, but what is the belt tensioner? Is it the small pulley (Item number 8 in the picture)? Or are we talking about the whole assembly. (Item number 5 in the picure).



Im mulling over wether or not to convert the car from an automatic to the Getrag 5 speed manual.

Part number 8 is just the idler wheel/pulley. The whole assembly is more like number 5.
Photo of my old one from my '93 2.3 8v.

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Thanks for posting the pics, much appreciated. How much roughly do those belt tensioners cost. Also is it a fairly straighforward job to change?

Should my mechanic take responsibility, or should i put it down to just one of those things and bear the cost myself?

I paid $196.40 plus tax for the last one several months ago. I can do mine pretty fast, maybe 15 minutes tops. I do my own repairs anyway. As far as responsibility, it's one of those things that you don't know until you get in there and start removing the belt. It could have been on its way out when you took the car in.

Check yours first. Mine was easy to tell that it was bad because when I went to tighten the belt after replacing the A/C compressor, the adjusting rod started coming to the top of the adjusting nut....never a good sign. The rubber was torn and the assembly kept turning.
If your belt tightens and you can push down on the belt and the tensioner returns to its original tightened position, then it should be OK.
One important thing about the tensioner is that you have to make sure you unloosen the lock down bolt first before turning the adjustment nut, and re-tighten the lock down bolt when finished. The plastic tab in front is for reference, move it to the small mark on the left of the tensioner housing when the belt is loose, then tighten the belt until it reaches the wide mark.
I stop mine just before the wide mark...I don't like putting too much tension on the rubber if I don't have to, and I've never had a loose/squeaking belt problem.

Dave

__________________

1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Thanks Dave,

Luckily i can get it for around $90.00. Going to buy it and take it to my mechanic. Going to change the cheaper shock absorber first. If that cures it, great...I can get a refund on the other stuff.
Out of Interest can this situation cause any damage to anything?
Many thanks as always :-)

noise is probably the small shock absorber...

it's hit and miss on the belt tensioner when you change the water pump. I changed out two pumps in the past two months... one car needed a tensioner...the other did not..

basically if your belt is tensioned properly...i would just put the new tensioner in the trunk..

the belt likely won't loose any tension because of the big lock down bolt...

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

Thanks Lee,

Very informative indeed. Will this situation have caused any damage?
Appreciate your time on this.

nope....no damage....

you maybe able to just get a rubber bushing for the shock absorber...i have done that... get a flat head screw driver and press it against the shock absorber at the top bolt... if you can get the vibration to stop there.... you can add a rubber bushing to the back of the bolt.

if your tensioner is shot.... your belt won't tighten enough... it should be pretty obvious if it is loose... check with engine off.... see how much play is in it.

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

Thanks Lee,

Its funny you should mention that. I did check the play with the engine off and there was quite a bit of play. A lot more than i can remember when i did this last time.
So i need a belt tensioner then? Item number 5 in the picture that i posted?
Someone told me it takes all day to change this part...SURELY NOT! LOL

Hi Zak,

When you press down on the belt look at the rubber tensioner and see if it twists and returns to the original position. It has been my experience that when the tension is shot, the tensioner moves and doesn't return because the rubber is torn/broken.
If the belt is loose, un-tighten the large lock down bolt and try tightening the adjustment nut. If it keeps turning and the belt doesn't tighten, the threads of the adjusting rod will start appearing at the top of the adjusting nut.

Yes, it could take all day if it is the first one you've replaced. It's like anything else, the second time is faster. The 4 cyl. is easy, but I understand that the six is a little more involved.

Good luck,

Dave

__________________

1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Hi Dave,

I wont be doing it thankfully, but my mechanic will. So how how long should it take an experienced mech to do this!?? just so i have an idea...
Will change the little shock absorber first then move on from there!
What a rigmorol!