Is my 1.8L timing belt tensioner broken ?

[RacerM]

I just replaced timing & balance shaft belts, and a leaking front main oil seal on my 94 Eclipse with the 1.8L SOHC. I'm concerned about the timing belt tension. When I put the new belt on, I had to pry against the tensioner pulley to tighten the belt, while tightening the adjustment bolt to secure the pulley bracket. The belt seems tight at this point, but I suspect that the tensioner spring is broken. What I don't understand is how the tensioner can work--once the tensioner pulley bracket adjustment bolt is tight, isn't the pulley locked in position?

FYI, the timing belt installation section of my Haynes manual says, "Loosen the tensioner hold-down bolt and nut to apply spring tension against the belt. Retighten the bolt"

Anyhow, is the timing belt tension going to cause problems for me down the road, or will it be O.K.? FYI, I've driven the car a few miles with the new belts with no problem, except for a somewhat noticeable high-pitched whine, probably from one of the two cog belts.

 

[Nt-Eclipse-Dail]

FWIW, I adjusted my belt tension the exact same way that you did (pry it over and then tighten the bolts down), I also had a 'slight' whine noise when it was all over and done with (not very loud but noticeable), and like you, I do not really see how the tensioner could work after everything was all tightened down...

My thoughts are that the 'noise' we got was probably due to overtightening of the belt. I tried to search for posts about the 1.8l belt tension and got nowhere. The good news (in my case) is that after a while the belt noise subsided and eventually dissappeared, and I have so far put about 20k more miles on the car and had no new problems or issues. I did not loosen my belt, I think it may have just stretched after a while resulting in less noise.

I have no way of knowing exactly how tight you got your belt, so I can not really say if it is going to cause you problems down the road or not. I was just sharing my experiences with the same exact issue. If your belt is making a lot of noise, I would recommend experimenting with the tension a little to see if you can get rid of some of it.

I hope I helped you some here, I was trying...

James

 

[RacerM]

Thanks James--good to hear that you have some miles on your engine with similar timing belt tensioning.

I was hoping that someone had access to a factory repair manual. They usually have detailed instructions regarding tensioning a belt--esp. a "critical" timing belt.

 

[Nt-Eclipse-Dail]

I wish I had that manual as well... I have been looking for a used one on the net but have not found one for the price I am willing to pay as yet.

I had read on this site that our 4g37 engines were 'non-interference' engines. That is that the pistons and valves never occupy the same space, and IF one of our timing belts was to break then the valves could NOT contact the pistons anyway (lucky for 4g37 engines).

If you search on the key words 'non-interference' the posts that I am referring to should come up for you. Posts like this one:

if you slipped timming it won't hurt it or bend any vavles, its a non interference motor... so if it did slip all u would have to do is time it correctly and it will run normal again, but thats just if thats the prob...

I would still suggest that you loosen the belt up a little and see if that reduces or eliminates your belt whine, but at least we can be a little more comfortable with our engines knowing that IF our 4g37 timing belt does break we will not be having to buy a bunch of new parts.

Hope you get it all worked out OK with your ride, let us know what happens when you get finished up.