Even if it doesn't fix the howl, those issues would have caused problems eventually so good job you found them!
Check your exhaust manifold nuts too as they are prone to coming loose.
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Even if it doesn't fix the howl, those issues would have caused problems eventually so good job you found them!
Check your exhaust manifold nuts too as they are prone to coming loose.
Where do I start..............
Turbo is back together.... Simple job to be fair.
Used this guide
http://www.volvohowto.com/how-to-ref...70-v70-or-c70/
Biggest hassle was getting the exhaust and inlet compressors/blades to line up. (Alignment recorded prior to dismantling). Eventually lined up and tightened. Kept twisting slightly when I was on the final tighten of the nut.
Got it back on fairly easy. Turbo oil return pipe was a git as usual. All the other pipes seemed to be suddenly in the way.
Coolant topped back up and then noticed it dripping from the firewall heater core junction thingy........ Now I know where the gentle little hissing was coming from when I was trying to get the Turbo off. The brittle plastic has cracked on the female lower part. Once up to temp, the coolant was pouring out.
Plan B. Joined the two coolant pipes together with some heater hose that I luckily had. No heating for a while. What are windows and sunroofs for!!?
Out for a drive. Quite quickly realised that......... YUP, car still howls........... Grrrrrr....
Turbo is boosting well so that's a bonus.
I have replaced the DIY RIP with the original pipework once before during the long on going hunt for the howl. It still did it. The only thing that was always on the car was the throttle body boost pipe. Could this be the cause? Going to fashion a replacement. Got one other idea too.
Shall be saving that for tomorrow. My forearms are battered. Few knuckles bashed.
The search continues......
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Few pictures. I got the rebuild kit from the UK. Turbo rebuild kit. £30 with SD by 1pm. Impressed with the quality.
Bloody hell, you don't mess about :)
I've used TurboRebuild before, had no issues.
My heater firewall connection was also broken when I put my rebuilt engine back in. Filled the thing up with new coolant for it all to empty out again lol. What I did was to remove the plastic firewall connector altogether and use some hose to go through instead. Bit fiddly but works to this day (still on the list to do).
Shame about the howl.
Have you checked the small elbow at the end of the manifold (behind the steering pump)?
Yeah, heater firewall connector will be gutted and pipes put in. To be fair, I thought I'd busted the heater core. Pleased to realise it's just some junction box. Apparently not a bit job.
The elbow on the inlet manifold is fine. I had the manifold off not long ago checking all gasket, PCV and pipes to make sure it wasn't that causing issues.
It is so loud the only thing it can be is boost related, boost pipes or joins.... No small leak could be so loud.
Gonna try two things today to see what happens...
Subtle little whine from the turbo on low revs as it spools up??? Praying its just "bedding" in..
Tried two other things with boost pipes. No change. Rapidly loosing the will...
Just a quick thought, there are some non return valves that are part of the evaporation system. One is clipped on top of the fan cowl and the other (if your car has it) is in the hose from the same valve to a T connector which then goes to the turbo inlet pipe (see pics, ignore the arrows).
These valves allow flow from the evap canister into the intake system when it is under vacuum. When on boost these valves stop the boost going into the evap system (mainly the one on top of the fan cowl). These valves are known to fail.
It could be your valve is making a noise when the boost is higher. Maybe try blocking the pipe from the inlet manifold (bung it with a bolt is what I did) to see if that is the issue?
Another thing to check is the vacuum "tree" on the top of the inlet manifold. The seal where it enters the manifold is a failure point.
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Non return valve on radiator goosed. Blocked off both ways. No change.
Put old boost pipes on with original routing. No change...
Grrr... Need a rolling road. If I only knew where the noise was coming from it would help. Think I'll get it on a ramp next and have a look...
Last time I checked (some years ago) each valve from Volvo was about £30. I could not justify that cost for my car so bought some 6mm fuel check valves off ebay for £2 each.
Have you pressure tested it yet? You can DIY by blowing into the intake pipe (sealing you face around the pipe after the MAF (after cleaning it of course), bit caveman style but works). I did it myself and found a couple of leaks.
Vacuum tree leaking a lot... Bubbling nicely under pressure when blowing down inlet pipe... Cave man style... Tried to make a pressure bung but it was useless....
New seal on vac tree and refitted.
So through process of elimination I have tried the following:-
By passed the intercooler leaving the turbo feeding directly into the throttle body. Using three pipes. Howl remains so it's not the intercooler.
Removed the plastic air intake pipe and used a short angle pipe with MAF on the end. (not ideal I know). That eliminated the air intake pipe and air box. Howl remains.
The only thing constant in all of this is the throttle body pipe... I have closely examined it. No apparent splits. Could the sound be the boost rushing past the little tube that comes off and goes to the idle control valve???
Like blowing over an empty bottle!?? It is that kind of sound...
My next thing is somehow trying to eliminate this.... I have managed to replace one of the idle valve pipes with another pipe that effectively blocks it. Just waiting for the battery to charge as I left the ignition on whilst doing something else (battery is goosed). Maybe the boost is howling through the idle valve....
Lol, crazy I know but it works :D
Is the idle valve clean or does it have lots of dirty deposits?
Have you taken the throttle body off and checked the gasket
Another thing I'm thinking is maybe it is before the turbo inlet? Some kind of leak which howls once the turbo is sucking lots of air. A split in the intake hose or maybe the PCV valve/pipework by the turbo is leaking.
Other than that, something in the exhaust...
Got any pics of the engine bay and down the back of the engine?
Had throttle body off yesterday also. Gasket is spot on.
Eliminated the inlet pipe so it can't be that making the noise. Didn't have the PCV pipes connected when I did it so it can't be them either....
Idle valve will be blocked and tested later today.
Will take some pictures of the engine bay and post them.
Keep the suggestions coming... :smile:
Must be getting close now :band:
Note........ Don't block idle valve pipes because the car gets no air and wont run.... Hahahaa... School boy error.
Idle valve removed, carb cleaned and lightly oiled. Other than being a bit oily it seemed fine and wasn't gunked up.
I know the pin is missing off the wastegate arm........
See my heater matrix bypass.... Works a treat until I can fix it properly. :smile:
If you haven't guessed.... Still howls....