Slight burning smell after timing belt change

[IZichard]

So yesterday I changed my cam  seals and crank seal. While I was in there I also fitted a new cambelt, 2x smooth idlers, toothed idler and small smooth idlers. Set the timing and put it all back together with new coolant.

All was well, started her up and timing was sweet, filled and burped cooling system then took for a ~20km drive. Drive was fine.

After the drive there was a bit of steam rising from bellow radiator cap (near the turbo) figured it was just spilled coolant on the hot exhaust, all good. But there was also a very slight burning rubber smell from passenger side of motor. I pulled off the passenger side timing cover and noticed what appears to be rubber deposits on the small smooth idler.

 

Inside passengers timing cover looking towards crank.

I checked and I can still spin this idler, there is a little friction from the belt but it isn't seized or anything.

 

Water pump still smooth no deposites.

 

Anyone got any ideas of what could be wrong here? or is this normal wear in for a new belt. As I said I have only driven ~20km.

 

Also how much play should be in the belt once the tensioner pin has been released?

 

Thanks

Edited October 24, 2016 by IZichard

[IZichard]

Scraped it off with my fingernail then went for another drive. It didn't come back so I'm figuring it was just the belt wearing in... 

[loner]

Check the clearance of the crank gear cambelt guide... looks a tad close on one side. You may have damaged the cambelt.

[IZichard]

I spaced it out to 1mm clearance on both sides. I measured a couple layers of card with calipers then packed between the belt and the guide and tightened it down. That is what I read the spec was, should it be gapped more than that?

edit: it was actually just over mil that I spaced it, like 1.1mm on the calipers.

Edited October 24, 2016 by IZichard

[loner]

1mm is good.. but it's not normal to have burning smells or melted stuff on the belt. I would take off the belt and all the pulleys and idlers an inspect.

[IZichard]

Yeah fair enough I'll pull of the crank pulley and all the timing covers tonight

[IZichard]

Pulled the timing covers off. Removed the crank guide and there were signs that it had been rubbing with the belt. I reinstalled the belt guide and double, triple and quadruple checked the clearance between the guide and the belt. Clearance is spot on. I checked all the idlers and they are all fine. Then I put it all back together and went for another short drive. Still getting rubber build up on the small idler.

I am starting to think that the reason the belt is contacting the guide is that the tensioner is not tightening the belt correctly.

 

How much play should there be in belt once the tensioner has been set?

 

I remember when I pulled the pin on the tensioner there was no big belt movement as it tightened, should there have been?

[94 Leone]

It should become tight, you did get a genuine kit from subaru right? Did you wind the engine over by hand at least one full revolution before starting the car? the slow movement helps the tensioner set
 

[loner]

I have never noticed anything dramatic happen when pulling the pin... there should be very little play in the belt... after a few turns of the crank

it should be at full tension. I can't find a specification for the belt tension in the manual, but there is some stuff about how the tensioner should

behave. Are you measuring the guide clearance on both sides? I think you should buy some proper feeler gauges.

 

 

[IZichard]

50 minutes ago, 94 Leone said:

It should become tight, you did get a genuine kit from subaru right? Did you wind the engine over by hand at least one full revolution before starting the car? the slow movement helps the tensioner set
 

Yeah genuine tensioner from partsouq. Probably wound it over 4-5 times by hand before starting.

 

37 minutes ago, loner said:

I have never noticed anything dramatic happen when pulling the pin... there should be very little play in the belt... after a few turns of the crank

it should be at full tension. I can't find a specification for the belt tension in the manual, but there is some stuff about how the tensioner should

behave. Are you measuring the guide clearance on both sides? I think you should buy some proper feeler gauges.

 

 

What does the manual say about how the tensioner should behave? I was measuring wrapping around the belt, so clearance was gapped across the whole width of the belt, and along the whole length of belt that the guide covers. 

 

Yeah a proper spacer tool would be good, just to be sure. Anyone have a spare they want to sell me or know somewhere that sells them seperate to a kit?

As for the proper feeler gauges, I was using a good set of vernier calipers to measure my spacer.

Edited October 25, 2016 by IZichard

[loner]

I use the 2004 STi manual... and they are US spec manuals... but as close as I can find. JAP stuff is all in Japanese

Most of the info is applicable...