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3.4 v6 cambelt and other work


Active Member
Oct 11, 2022
Country Flag
Hello, looking at getting the parts for replacing the cambelt on my Colorado 3.4 v6
I am at 170000miles (owned it from 160000) and don’t know when the cam belt was done last. I know that the engine is non interference so even if the worst was to happen it shouldn’t be a major drama but kern to avoid minor drama too…
Main parts needed should be new belt, tensioner, idler pulley?
I suppose it would make sense to replace the water pump, thermostat and belts (Aircon, water and steering) too?
Anything else that should be looked at while getting in there?
I read about swapping the thermostat for a lowering temperature one, is this advisable?

Any suggestion on suppliers?
Milners seem to have the belt and tensioner and pulley but no water pump
Seems to be a relatively simple job any specific tips?
Thanks in advance!
Has the radiator been changed*? A good opportunity to replace it, if it's the original rad.

*As it's the 3.4v6, I assume it's also an auto.
Hi Chadr, thanks, very good point about the rad! It was changed by the previous owner about 3 years ago as he did have the dreaded coolant-trans oil soup. The rad was done at the time together with a (very expensive!) full rebuild-refurb of the auto transmission. Was planning on doing a coolant flush when doing the cam belt as coolant will need to be renewed replacing the water pump.

I was thinking also of changing the crankshaft main seal as we’ll be in the neighbourhood…
Take a look at the supplier Roughtrax. Many people use them here with excellent experience.
Thanks, yes roughtrax and milner are the two suppliers I normally look at but neither seems to list the water pump for my engine… I found some on eBay but not sure if trusting aftermarket products… would hate it to start leaking 6 month down the line…
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Reporting back… so I have gathered all the parts needed from a mix of Milner, roughtrax and autodoc.
I found a mix of oem and aftermarket parts. Timing belt is a full kit from skf, I read of people with good experiences from it and comes with belts and both idler and tensioner pulley.
Water pump is aftermarket, will see, bus seems to be popular on US 4Runners so should be fine.
As I have a little bit of weep from the valve covers I’ve added cover seals and related bits to the shopping list too. Will be a pretty major service and should help to keep the v6 purring along nicely..
Should get around doing all the work in the next few weeks.
realized I never reported back... so all major service done. no more weeping from the valve covers and new timing belt, idler, tensioner,waterpump, thermostat, drive belts... happy engine!
I was glad I did it at a mechanic friend. The timing belt was mostly straightforward, it would be really easy if reusing the tensioner and using a spreader to losen it but to reach one of the two bolts on the tensioner you need to take off the whole cradle of the aircon pump. I think it was 6 bolts. quite a pain. but all got in and out ok. coolant was perfect with no deposits.
doing the rocker covers was fiddly but not tricky, all was clean and tolerances were still good at 170000m. should be a while before needing reshimming.
I am fairly confident the timing belt was the original one. a bit of perishing/ cracking on the surface but could have gone on for quite a while still. very impressive!

throttle body was very nice and clean, changed the pcv valve and gasket and as I had the parts I've taken off the intake muffler, the intake sound of the v6 is much nicer now, baby tiger growl compared to a V8 but has a nicer note then with the muffler. swapped a bunch of vacuum lines... looking nice and healthy.

I'm waiting now for a new alternator, I finally found one for the 5vzfe that outputs 80A instead of the 60 of the standard one, I'll keep the old one as spare, it works but clearly a bit tired as voltage is never going above 14.1
I've got to do this job at done point, how did you loosen the crank bolt?
A good impact did the tool, it’s easier if you take out the rad that will be drained anyway. You may need an extractor for the pulley too. Mine came out with gentle taps with a soft hammer but they can be a bit sticky.