1998 V70 XC Resonance 2300-2900 rpm, fuel pump, etc.

[superfeed]

Good People,

Friday morning I pulled the prop shaft as the viscous coupling and center bearing support are not good.

Drove the car about 500 miles this weekend. This is the first shakedown trip with my replacement motor.

I am having a difficult time telling if or when the turbo is coming on and off. As I recall, my 96 850 was very obvious. Could it be inoperative?

I also note a resonance from the front when accelerating through the 2300 rpm to 2900 rpm range. The exhaust note gets louder and it makes it a little hard to judge whether the car is laboring through the range.

I was wondering if a bad bevel gear bearing might cause this sound. The car was driven with a severly tweaked front subframe, with a donut on, for many miles after hitting a curb hard.

The front driver's side axle CV joint boot is bad. Could this cause the sound?

Also have Code P0455 which I have not yet addressed.

One more thing...,

The fuel pump is pretty loud..., are good fuel pumps audible in the cabin?

Thanks!
John Gregory
Portage, MI

[superfeed]

Anybody?

[scot850]

Lots of questions and lots of possible answers, so probably best to break it down into smaller chunks.

Are there 2 main issues you are trying to fix here + the P0455?

I believe your questions are:

1) Vibration resonance at 2300-2900 rpm. Is this in all gears or 1 or some? There are a host of possible sources so to help me and others lets do a little base-lining.
You have removed the VC and Prop-shaft due to failure of one or both? Have you changed the whole engine and if so, did you keep the old trans and angle-gear? Do you feel the vibration through the steering wheel, gas pedal or seat of your pants?

From this start we can start to look at possible issues from possible bent front frame (sounds like you hit a curb), to bent wheel, or engine/mount issues, to trans issues.

2) Possible issue with turbo not kicking in? Again, are the parts all transferred from previous?

Once we make some headway on this we can look at the P0455 issue.

Lastly, have you serviced the engine, brakes, suspension or other items in the drive-line?

Neil.

[superfeed]

Hi Neil,
Thanks for your response.

I am trying to be very aware when the car seems to get louder (and bog down maybe?) in the 2300 - 3000 rpm range. It doesn't seem to do it all of the time. I guess I could try holding it in the low gears to see if it is gear related.

I bought the car knowing it had whacked a curb, but my too quick of look didn't see that the subframe was bent up front. I was thinking I could just replace the control arm.

I ended up finding a subframe in good shape and replacing the passenger side control arm too.

After some research I became well aware of the problem with different sized tires. Unfortunately the previous owner drove many miles with the donut and tweaked subframe. The alignment was off so bad that the donut was shredded.

I drove the car for a week after replacing the subframe. It seem to run well, though I suspected a bad wheel bearing on the front passenger side and I thought the rear emergency brakes were hanging up.

Shortly thereafter, lol, I burned up a couple of valves in a particularly aggressive freeway entrance.

I replaced just the engine/turbo unit with one that has 77,000 miles (the car has 213,000). I pulled the engine and trans out from the top. I just started driving the car again recently.

I replaced the passenger side wheel bearing and it took care of a lot of vibration from that side.

I took apart the rear brakes and removed the e-brake hardware. Everything was quite rusty (Michigan), but intact.

After taking the drum brake stuff out, the clunking when changing from reverse to forward brought me to believe the viscous coupling was shot. I removed the prop shaft and no more clunking.

I did the front brakes last year and the rear look ok.

It has been a few years since I drove my 96 850 Turbo wagon, but I remember it being smoother than this.

I am not feeling any vibration in the wheel. I had Firestone in Kalamazoo align the wheels. The car cruises beautifully at highway speeds and seems to have good torque.

I am wondering about the bevel gear and may remove that sucker too! I should have done it when the engine was out, but I was hoping to keep the AWD...

The P0455 code I will troubleshoot soon enough, I was wondering if that code ever is accompanied with weird performance in the rpm range that I think I am having a problem in.

Thanks for caring!
John

1996 850 Turbo Wagon - Sold
1986 240D 123K Driving. Needs rust abatement on rockers and floors
2002 S80 2,9 Normally Aspirated. Daughter is driving. Needs rear upper shock mount and vacuum brake booster pump.
1998 V70 XC - Now FWD

[scot850]

Have you checked all the engine mountings? The one under the crankshaft pulley fails and will cause a horrible vibration in the rev range you are talking of. Also the top torque mount can do that to, but to a lesser extent. Look carefully at both as they can look ok. Remove the RH front wheel and gently jack the engine on a block of wood under the oil pan and see if a gap appears under the crank end engine mounting.

Neil.

[draser]

I'd repair or replace the cv joint as it may cause the vibration you mention. Since you removed the prop shaft the read diff, or bevel gear, should not make noise as there's no load on it. And you noticed noise coming from front. Motor mounts is also a good suggestion after hitting a curb.

[superfeed]

Thanks guys.

I'll replace the axle on payday and check the engine mounts in the meantime.

John

[JRL]

I was going to say this but someone beat me to it
I'll lay odds that your lower engine pad (right side of the car engine mount) is completely shot.

When this happens the engine is actually resting on the subframe and will vibrate and make noises in that RPM range.
If you open the hood and look closely, I'll bet you can see the engine tilted towards the right side of the car.

As for your turbo, did you re-adjust your wastegate rod with all your engine and subframe changes?
I'll bet if you tighten the rod a couple of turns you will feel the turbo once again