1989 760 turbo - won't go over 3k rpms

jetlag · Post by **jetlag** » 19 Aug 2015, 16:50

Hello, I just bought a Volvo and I'm having some issues.

The previous owner had a new cylinder head installed before I bought the car.

It will not go over ~3000rpms. When driving part throttle and easing it around and keeping the car out of boost, it drives normal. If the turbo gauge shows even a fraction of boost, the car bogs. This usually happens around 3000rpms.

The RPMs will struggle to go up to maybe 3500 or so, but the speed will not increase.

When sitting in Park or Neutral, the engine will not rev over ~3000. It almost seems like hitting a rev limiter.

Any ideas? Turbo has minimal shaft play, new spark plugs and wires.

lummert · Post by **lummert** » 19 Aug 2015, 19:03

Have you checked the boost hoses for leaks from the turbo to intercooler to throttle body?

jetlag · Post by **jetlag** » 20 Aug 2015, 17:04

I found a very large boost leak today from the intercooler to the intake. I'm hoping it will solve the problem completely. Unfortunately, I could not find a suitable coupling today so I had to order one on Amazon.

lummert · Post by **lummert** » 20 Aug 2015, 21:31

A boost leak will cause the problem your car is having.

jetlag · Post by **jetlag** » 20 Aug 2015, 21:33

lummert wrote:A boost leak will cause the problem your car is having.

Especially if I could stick my thumb in the hole on the coupling?

I'm embarrassed that I didn't spot it sooner, but it was hidden on the bottom of the coupling and had some crud on it.

jetlag · Post by **jetlag** » 22 Aug 2015, 14:20

Problem solved! I got the new coupler in today and the car runs great. Now it makes me want to mod it..