I changed the timing belt & associated other parts over the weekend on my '
99 S70, and thought I'd share some observations I made during the process to
help others contemplating "doing it yourself". :)
(Many thanks to Tim C. for sending me the detailed instructions for the
mechanical tensioner version!)
First off, let me say that there is confusion here in the states regarding
hydraulic vs mechanical tensioners on 1998-2000 S70's. Although I have seen
info on the web that Volvo switched from hydraulic to mechanical tensioners
sometime during the 1998 model year, specifically with engine # 1266128,
both Volvo dealers here in San Diego state that this is not a certainty.
They cite instances of servicing 1999 S70's with hydraulic tensioners.
Anyway, mine has the mechanical, but I didn't end up buying the parts until
I had the cover off, which meant I had to pay dealer prices.
This car just turned 105K miles; which is the recommended service interval
for the timing belt according to my manual. I wouldn't normally wait the
full interval, but at my last plug change at 90K, the timing belt looked OK.
(It still looks OK, with only very light cracking under sharp bend) Can't
say the same for the serpentine belt; it should have been replaced a long
Since I had it apart, I decided to replace all moving parts:
- Serpentine belt
- Timing belt
- Idler pulley
- Water pump
Total bill for parts = $ 450. The water pump was the most expensive item.
Total time = 5 hours. (if I had to replace just the timing belt on my S70
again, I believe I could do it in under an hour; maybe as quick as a half
Preparing for this work, I brushed up on the general procedure with the
Volvospeed, Bay 13 info for an 850. Let me just say that the 850 procedure
is really not relevant to the S70. I'm glad that Tim sent me the info, as it
helped out dramatically.
I have seen numerous references that the belt can be removed without
removing the crank pulley. I investigated this first, which ate up a half
hour of my 5 hours, and I believe that it is either not possible or a total,
royal pain in the ass. The reason is that there is a fuel line that runs
just under the lower belt cover that is not there on an 850. I investigated
loosening the brackets for the line, but still it wouldn't move much. So I
gave up and went the "remove pulley" route. (I only really spent the time to
see if could easily be done)
Let me just emphatically state that if you have an impact and a 6" puller,
the "remove pulley" route is the ONLY way to go! Since I was timing
everything, I noted the time when I started to remove the pulley. It took me
exactly two minutes to remove it, which included marking the crank nut. It
was far easier to remove than many other cars I have worked on. Note that I
used the impact to remove the four bolts as well, which speeded things up.
The pulley is only on with a very light interference fit.
A comment on timing marks. The Volvo engineers really did a horrible job on
the crank end. With the pictures on Volvospeed of the 850 with hydraulic
tensioner, you can see the mark pretty readily. With the later mechanical
tensioner, the belt angle obscures your vision, so you cannot see it
straight on. Why didn't these dumbasses put the mark directly vertical, i.e.
at 12 o'clock position? Then you could be assured of no parallax error.
Anyway, with the mark aligned with belt off, the roll pin on the pulley is
at 12 o'clock, so you can use this as a check after belt installation.
The only tedious part of the job was the water pump. This took me the
longest time of all. It has seven small screws with sealant material on the
threads, which take a long time to remove. (I would have used the impact
ratchet, but by this time it was late at night & didn't want to wake the
wife & kids. I have a big 5HP industrial two stage compressor mounted in the
loft of the garage, & it tends to shake the house a bit when it runs)
Removing the pump naturally leaves part of the gasket on the block, which
took forever to remove. Additionally, it takes a bit of fiddling to figure
out how to get the pump out of the general area. Hint, move it to the right,
then up to clear at an angle. Plus, even though I drained most of the
coolant, I still ended up with a big puddle of coolant when the pump was
Inspecting the water pump, tensioner, and idler, I determined that all were
still serviceable, but wouldn't feel comfortable that any of them would make
it another 50K miles, let alone another 105K. BTW, when I was at the Volvo
parts counter, a mechanic came up to the counter for parts, noticed the
tensioner in my hand, and said "you are replacing that when you replace the
belt, right?) I stated I was, and he said, "good, there was a problem with
them blowing up after 100K, so Volvo now recommends that the tensioner be
replaced along with the belt." I told him that I was replacing the water
pump and idler too, and he said "if it was my car I was working on, I would
do the same thing"
After fiddling with the belt for about 15 minutes, unsuccessfully trying to
fit it, I came up with a trick that made the job far easier. (The problem
was I couldn't apply any tension to the belt on the crank to intake cam side
without the belt invariably slipping off the crank end a tooth.) I went to
the wood scrap bin & pulled out a short piece of 1/4" thick hardwood, and
wedged it between the lower belt cover and the belt (at 6 o'clock position
on the crank pulley), which held the belt tight against the crank. Now I
could apply tension to the belt, slip it on the intake cam pulley, then back
down at the tensioner, then the water pump, finally the exhaust cam pulley.
(note; I held the tensioner pointer to the right to give it more slack) With
this trick I was able to fit the belt in about a minute with no hassle or
Adjusting the tensioner is quite easy, using a 6 mm hex key rotating it
against the stop, then back until the pointer reaches the middle slot
(between the tabs). Then rotating the crank a couple of times thru & recheck
that it hasn't moved.
One cautionary note; I noticed as I was turning the crank in the final steps
that the belt had picked up a small blob of oily mess from the seepage
around the crank seal. While it was not large, any oil on the belt is not
good, so I would recommend thoroughly cleaning around the lower crank area
to prevent this from happening. Plus, if I was doing it again, I would
replace the crank seal at the same time. (it is not leaking per se, but
there is a bit of seeping going on.)