Timing belt questions

[oragex]

Thanks for answering JDS, I went through the first link but it rather says changing it is not needed with the first belt. There is one talking about non oem replacement pump that failed and another one talking about a pump failing at 130k which is surely another replacement pump at these miles. I have yet to read on forums about an original pump that failed in between the belts changing interval. However if there are people willing to replace parts just for the peace of mind, that is also a point of view. I know people replacing the belt at 80k miles rather than 100k miles, it's just another way to see things.

[cn90]

@oragex,

Doing a survey on Aisin WP is similar to looking at human lifespan poll. Some people live to 100 years old and some die at the age of 10.
Median lifespan in the US is about 76-78 years old or so.

At 100K miles, I have 2 options as I am the DIYer:
1. Replace the WP at 100K miles, then at 150K (5 years from now as I drive 10K miles a year), get back in there and install a new Aisin WP.
2. Replace the TB and pulleys x2, and install a new Aisin WP at 100K miles.

Personally, I don't see anything wrong with either technique as long as you are the DIYer and have time to play with it.
If you use a mechanic, then it makes sense to replace the WP at 100K.

Back to the Factory WP debate, I will try to stay neutral and unbiased.
Just read the thread below and will quote relevant comments from that thread...

Poll---Water Pump Failure:
http://forums.swedespeed.com/showthread ... mp-failure

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The standard for any Volvo tech I've ever meet (including myself) is to inspect the pump on the first belt change and replace the pump on the second belt change. I can count on one hand how many issues with water pumps I've seen between those intervals. Aisin makes the OEM water pump, don't use anything less!!

Mine started weeping a while ago in the 155k-160k range. I have a new one on my bench to go in, just waiting for a warm weekend.

Mine at 130K has some bearing play, replaced it.

I put a non OEM water pump in my T5R at 120k (replacing the factory unit which was in great shape......) and at 180k the engine started making the most hellacious rattling sound that seemed like big end small end and valve trail failure all the same time. I found a private party low mileage T5- the owner said he bought but did not need because his T5 was making the most hellacious sound ever but when he pulled it out he found a non OEM water pump eating into the block so he fixed and put it back in. So I held off on buying the motor, pulled the water pump, and the bearing had majorly failed letting the stainless impeller start eating into the block. So- YES! OEM only.

[shoebox]

I find this thread very helpful. I recently got a 04XC90 2.5T. It currently is approaching 69K miles. Anyone heard of timing belt failure below 100k miles that are over 10 years in models that share same timing components/engine?

[tardcart]

my friends 06 xc90 had 180k before my pleas made him change it and he was pissed because the timing belt looked brand new. that was ;last year so rest easy. maby at 100k.

[cn90]

Best is to remove the cosmetic cover (Torx bolts) and inspect the TB for surface cracks.
I posted photos in the TB DIY thread to show people what surface cracks look like.
If you ever have cracks, they are on the smooth side (not the tooth side), which you can easily see once the cosmetic cover is off.

[shoebox]

tardcart:
That is reassuring. Did he ever replace the tensioner prior to 180k? Hopefully that represents the norm rather than very good luck!


cn90 :
Thanks. I understand the tensioner seems to be what causes the majority of timing belt failures. There is no way to inspect unless the belt is off?