Hello all,

To change or NOT to change the the HYDRAULIC TB tensioner at 60-70K miles interval. Unpublished but this is the conversation between myself and the Parts/Service dept at Shepherd Volvo in Oak Park, IL (Chicago suburb):

- 1998 Timing Belt should last up to 70K.
- 1998 Hydraulic TB tensioner should last to 90K. This is because they see some leakage at the age.

So "by-the-book" recommendation is: Change TGB belt at 70K and Tensioner at 90K.

I asked them so why pay for one service at 70K and another one at 90K for similar job?

Then the reply is: well we can "kill 2 birds with one stone" and do BOTH the TB belt and Tensioner at 70K.

Cost of the tensioner is $125.00 (FCP Groton's price). For this price, NOT worth to save this money and running a risk of having an otherwise good belt but a failed tensioner causing engine head damage @ a cost of $3-4K repair bill!)

If you DIY, then the labor is on you.

So I have my ANSWER: To sleep well at night, change BOTH TB itself AND the Tensioner at 60-70K interval (or if more than 6 years old).

cn
1998 V70 55K with HYDRAULIC TB tensioner

What Volvo instructors and reps will say is yet another thing. We techs were told that unless the hydraulic tensioner is leaking oil, it's then OK (NOT 90K miles).
I've only seen a few leaking oil and it's usually higher mileage. Most go well over 140K w/o any signs of leakage. There's a few with over 250K miles around here and still with their original tensioners.

You can't believe all rumors. Now, the '99 on up manual type tensioners are suppose to always be replaced with every t-belt at 105K miles.

This topic interests me and I'd like to chime in here with a couple of comments and questions...

(I have a colleague who lost his S70 T-5 TB and paid a huge price therafter, so I'm sensitive to this discussion).

My 1998 S70 T-5 has 84k miles and my local dealer tech told me that the hydraulic tensioners are good up to the 140k belt change. He also told me that they fail safe...they have a pin that keeps the assembly together even if the fluid leaks out of the unit. Consequently I haven't changed the tensioner, only the belt.

I've heard that the manual tensioners are a liability and need to be replaced at 70k, but not the hydraulic tensioners. This (thread) is the first time I've heard about changing the Hydraulic tensioner at 90k.

Do we all need to buy the new tensioner, like an insurance policy? What's real in this discussion? Are we to expect a small percentage of casulaties under 140k miles in the community of S/V 70 users out there? Do we just play the odds?

Back to you...

Clive
San Diego.

I suspect if we all ran out and installed a new one more
engines would be lost due to install errors then actual
tensioner failures had we done nothing. Change it at 140K
when you do the second belt (I have an 850 and S70 and that
is what I am doing).

Also, the timing cover comes off with one bolt. Takes 10 minutes
to inspect tensioner for leaks. You can alwyas do that.

Dear Clive,

I am in Chicago and I just have to rely on what I hear from the parts guy and service technicians at Shepherd Motors Dealer in Oak Park, IL who fix tons of Volvo everyday.

The Hydraulic tensioner is kind of a "gamble" with low risk of you decide to ride on it until 140K.

If you tell me between a new hydraulic tensioner at $125.00 vs a risk of blowing the engine head with $3-4K repair bill, then I'd play safe with a new hydraulic tensioner at 60-70K interval.

This may be "urban legend" but I'd think $125 on a new hydraulic tensioner is money well spent.

Just my thoughts....I want to sleep well at night.......

cn 1998 V70

If you're more comfortable replacing it now, by all means do it. IF I owned an interferance engine like that, I too would probably do the same thing. As for your initial question of "as a tech, how many have you seen fail"........NEVER! The engines that I've seen fail so far due to t-belt related problems failed for other reasons, usually because the owner simply failed to replace the t-belt, way past 70K miles. I've seen bad t-belt idler pulleys too.

Then, there's the problem of serp belts failing. If a serp belt shreds on one of these (ANY newer Volvo engine), pieces of the belt get under the plastic cover, under the crank t-belt cog gear and the t-belt skips, causing valves to hit. Now, THAT amazes me as the older 4 cyl engines (NON-interferance) had a plate under the lower cover designed to keep debris out. That idea was gone with all the newer white engines. Brilliant!

Just curious as a tech, how many Hydraulic tensioners have you seen failed at 60-80K?

From what I understand, a hydraulic tensioner may appear OK at 70K TB change but fails at let say 80K. Is this true?

Thanks again.

CN