Although I had reported here that I finished the engine swap on my V70R (see details here):
- and I’ve driven it about 375miles since
- and there are warning lights lit
- and it starts and idles fine, and revs fine – no misfires
…it still didn’t seem to have the full power I remember – granted, it had been 14months since the R had been on the road. There were occasional flashes of full power under throttle, but something just wasn’t still right.
Back in February, as I finished the engine installation for the first time (again, refer to the previously linked thread), I noticed that there was a vacuum hose that just seemed to be floating there – I couldn’t figure out where it was supposed to connect. I thought I had posted a question here about it, but I couldn’t find a related post (it would have likely been in the “What did you do to your R today?” thread. Anyway, here’s a picture of that unknown connection.
Today, I figured it out!! The engine donor (a 2007 S60R) had an aftermarket boost gauge – it was broken. I moved the engine over to our ’05 V70R and when I was all done there was one vacuum line that I saw, and I couldn’t figure out where it connected It was the Tee for the aftermarket boost gauge!
So, with that line vented, there was no way the turbo boost control solenoid (Volvo PN 30670449) could accurate control the wastegate!
When I got home I removed that Tee. In the donor S60R, the boost gauge line plugged into that black line sticking up.
And reconnected the boost control vacuum line directly to the solenoid again and tied it in place.
ALL the boost is back, now! 😃😃
To help the next person trying to diagnose similar symptoms, here are some of my other thoughts from during the troubleshooting process:
- I considered that maybe my catalytic converter was clogged. There just seemed to be so much power missing. BUT, the car started and ran fine, and it never bogged down, idled irregularly, never misfired, and never died out. When I’ve had vehicles with clogged catalytic converters before, they would basically start and run for a bit, but then as you would give it gas the engine would choke off and die out.
- I thought about whether the turbo was bad. But, above 3k RPMS I could feel the boost building. But it just didn’t have enough “oomph” below that.
- I saw in other threads to make sure that the knock sensors were connected, in case there was an issue there that was retarding the timing.
After ruling all those out, I remembered the boost gauge on the donor S60R, and it all made sense from there. I’m glad to have it resolved – it was the last thing hanging over me after the engine swap. Our V70R has a new lease on life and is running strong again!