98 S70 timing belt tension failure

98s70sc · Post by **98s70sc** » 11 May 2009, 10:12

Hey guy's awesome sight I wish I had found sooner.
Anyway, the auto tensioner for my timing belt failed at about 70-75 on the interstate last week. I have only dug into it enough to to know that it was the tensioner and not the belt. I'm assuming the valves are bent but have not gotten into head yet to see. At this point I'm trying to decide if the car is worth repairing. It has 156,000 miles and is in other wise very good condition. I have found a used head for $350. Has anyone had experience with this before and am i not thinking of anything else that could be damaged.

Post by **tjts1** » 11 May 2009, 12:20

Buy a complete engine. It'll be cheaper/faster/easier.

Post by **vegasjetskier** » 11 May 2009, 14:51

98s70sc wrote:am i not thinking of anything else that could be damaged.

Pistons, cylinders, connecting rods. I'd tear it down to see what you have before buying any parts.

Post by **renns** » 11 May 2009, 18:18

With the belt failing at higher engine speed, damage is likely to be extensive. I'd be inclined to swap out the entire engine as well. Just be careful to get the exact same model, or check to ensure the one you get is compatible with the engine control systems.

98s70sc · Post by **98s70sc** » 15 May 2009, 07:58

Thanks guys. I think I am just going to replace the motor. I can get one with around 100K for about $700.

jjjh2n · Post by **jjjh2n** » 16 May 2009, 20:48

I am probably wrong on this, but I thought that the whole point of the white plastic clip on the tensioner was a safety if the tensioner ever failed.

Post by **MadeInJapan** » 16 May 2009, 21:46

You are correct but usually if it fails, it fails and the white snap-on disc will make little difference.

Post by **wheelsup** » 17 May 2009, 14:13

Kinda pisses you off that Volvo didn't make an iron or steel version of that clip or extend the tensioner that amount so lost tension wasn't the end of the world. I wonder how many otherwise perfect engines were lost due to the tensioner failing.

Post by **Brucebo** » 17 May 2009, 14:42

wheelsup wrote:Kinda pisses you off that Volvo didn't make an iron or steel version of that clip or extend the tensioner that amount so lost tension wasn't the end of the world. I wonder how many otherwise perfect engines were lost due to the tensioner failing.

Does anybody have any knowledge, data, or just a gut feeling, on which of the two S70 tensioner styles is more robust/reliable, the older hydraulic tensioner or the newer, hand cranked manual tensioner?

-Bruce

98s70sc · Post by **98s70sc** » 15 Jun 2009, 09:04

Update.
Short version of loooong story.
Every valve was bent only 2 could be removed without cutting the ends off. So I went with a new "used" motor for $650 at 116k.
Replaced tension and idle pulley and auto tensioner, water pump, and belts also broke the reservoir on the power steering pump pulling the old motor out but the guy I got the motor from gave me a new one. Put the new motor in and it ran like a champ, the only problem is it had a major oil leak. Pulled the motor back out to find it was the rear main seal which didn't show any signs of leaking before. So replaced rear main $20 and transmission seal while it was out. I guess the moral to the story is replace the auto tensioner no matter the type when you do a timing belt. The original was a mechanical the new a hydraulic but for $80 while you are in the middle of it better safe than sorry with these things. Moral #2, while you have the entire engine out go ahead and replace all those silly little cheap seals and gaskets unless you just like doing things twice. Currently it's running like a champ and not a drop of anything leaking.