Help, my V6 won't start after new belts

A1tony · Post by **A1tony** » Fri Mar 16, 2012 1:10 pm

My mechanic is pulling his hair out !

Just had the cam/crank seals replaced with new belts, pulleys and hydraulic tensioner. My mechanic did the belt last year but the crank seal failure meant doing it again so it's not like he doesn't know how to do it ( also he has been my mechanic and friend for 17 years and is utterly trustworthy)

Bottom line is it turns over fine (turned by hand also on rebuild for safety), there is spark, compression of +90 psi, fuel ( the plugs are wet) but it just won't fire. It's not the alarm because it wouldn't turn if it was live. Either way I need it back and it's beeched !!!

Any peculiarities need checking or other ideas welcome., and fast !!

mikeWalsall · Post by **mikeWalsall** » Fri Mar 16, 2012 4:22 pm

Has he got the valve timing right as 90psi seems low .. at a minimum I would have thought around 130-135psi (14.7 x 9) ..

A1tony · Post by **A1tony** » Fri Mar 16, 2012 5:38 pm

Not sure on the Maths for right psi but I will pass it back to him. Problem is most of the components are held with Woodruff keys making it quite hard to get wrong. Still, it's a possibility !!
Thanks

Tony

mikeWalsall · Post by **mikeWalsall** » Fri Mar 16, 2012 7:04 pm

As rule of thumb .. 14.7psi (Atmospheric pressure) multiplied by the compression ratio of 9-1

If the valve timing is out the 24 valves will not seat properly ..

teenmal · Post by **teenmal** » Sat Mar 17, 2012 4:17 pm

mikeWalsall wrote:As rule of thumb .. 14.7psi (Atmospheric pressure) multiplied by the compression ratio of 9-1 If the valve timing is out the 24 valves will not seat properly ..

Hi Mike,

Good bit of information,what would be the psi on a 2.5td be?

Cheers.

mikeWalsall · Post by **mikeWalsall** » Sat Mar 17, 2012 5:39 pm

14.7 psi x 19.8 C/R = 290+ psi ..

teenmal · Post by **teenmal** » Sat Mar 17, 2012 6:01 pm

mikeWalsall wrote:14.7 psi x 19.8 C/R = 290+ psi ..

Hi Mike,

Thanks for the info but I thought a 2.5 Diesel would be more likely to be in the 400/450 psi mark.

I dont have my workshop WLT engine manual at the moment.

Cheers.

mikeWalsall · Post by **mikeWalsall** » Sat Mar 17, 2012 7:34 pm

Diesel 30 kg square cm @ 200rpm cranking speed ..

30 x 14.21 = 425+psi ..

Post by **Simon Jones** » Sat Mar 17, 2012 8:00 pm

Anyway, back to the original topic.....

It does seem like a timing issue. Has he re-checked it again? It sounds like you've got fuel, air and a spark but just not quite in the right order. Try calling Allan at http://www.allansvehicleservices.co.uk/ as he has lots of experience changing cambelts on the V6.

Post by **Doone** » Sat Mar 17, 2012 8:48 pm

The compression does sound too low.

Help, my V6 won't start after new belts

Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts

Re: Help, my V6 won't start after new belts