My V70 1999 2.4 Sounds like a Tractor - why?

bluebossa · Post by **bluebossa** » 06 Apr 2017, 04:54

Anyone heard similar to this before and can point me in the right direction?

Post by **oragex** » 06 Apr 2017, 06:18

Could it be a very loud serpentine pulley? Such as the a/c one. Does the sound go away without the belt (you can run the car at idle 1-2 min without the belt on). Another way to locate a noise is to use a 2-3ft tube (I use a shower hose) and carefully approach one end to the engine while listening to the other end at the ear.

Post by **Darkfleet** » 06 Apr 2017, 06:32

Sounds like maybe your exhaust header is cracked?

When cold pull the heat shield (1 bolt) and start it and feel for leaking air at the side of the head closest to the firewall.

bluebossa · Post by **bluebossa** » 06 Apr 2017, 11:25

Thanks but goes away after revving to 2k?

Post by **scot850** » 06 Apr 2017, 11:40

I would suggest one of 2 things:

1) Cracked exhaust manifold or failed gasket or broken flex-pipe in the downpipe. Rev'ing may just cover this issue.

2) More concerning may be lack of oil getting to the head. Raising engine speed may just increase oil flow to starved top end. Try running a thicker oil to see if it helps. The issue may be the oil pan 'O' rings have failed not allowing oil pressure to the head until higher revs.

Neil.

Post by **June** » 06 Apr 2017, 16:32

Sounds like a bad crankshaft pulley balancer. I heard the same noise on 2 family Buick 3800 engines and a friend's Ford and in all 3 cars the balancer had broken lose of the pulley the serpentine belt runs on. All 3 cars only made noise when idling and noise went away when rpm was increased. All 3 cars were normal after replacement and all three balancers had the rubber bushing between the balance weight and pulley was gone also with the engine off you could hand move the serpentine belt a few inches back and forth by hand between the stop pegs. Worth checking, June

bluebossa · Post by **bluebossa** » 06 Apr 2017, 19:01

June wrote: ↑06 Apr 2017, 16:32 Sounds like a bad crankshaft pulley balancer. I heard the same noise on 2 family Buick 3800 engines and a friend's Ford and in all 3 cars the balancer had broken lose of the pulley the serpentine belt runs on. All 3 cars only made noise when idling and noise went away when rpm was increased. All 3 cars were normal after replacement and all three balancers had the rubber bushing between the balance weight and pulley was gone also with the engine off you could hand move the serpentine belt a few inches back and forth by hand between the stop pegs. Worth checking, June

Thanks June - sounds promising... will check and report back