01 v70 2.3 t5 annoying rattle solved by accident

[belskee]

Hi my v70 2.3 t5 which I've owed since last December had a nasty rattle which couldn't be identified through poking and proding any of the heat shields.

Previous owner said he changed the cam belt 30 odd k ago but i changed the lot again for peace of mind hoping to find the waterpump or tensioner might be the cause of the rattle but no luck.

The car also had etm problems which thanks to this site it was identified and a sacer tps has fixed it, after this i had to replace the front o2, then i had maf (signal range too high) and overboost codes pop up getting fuel cutting out mid boost.

I ordered an uprated boost controller and some 4mm id vacuum tube but after fitting was still getting overboost codes, unpluged maf and overboost code went away but oviously had a new maf code.

I then decided to pull the turbo heat shield off and have a tinker with the actuator and wastegate, the arm was incredibly stiff so unhooked it from the wastegate to find the wg lever stuck shut.

All I could think of to do was to force it open using a long extension bar and hammer, 20 minutes beating it back and forth working oil around the lever it thankfully unseized enough to be able to opened and closed by hand, put the actuator arm back on and pressure tested the actuator to make sure it was working ok.

After putting everything back together I started the car and the first thing I noticed was the nasty rattle had completely disappeared, for id purposes the rattle was worse at cold idle and at low load, slightly less when warmed up and gone past 2500 rpm.

Im thinking it was the heat shield for the turbo even though I checked it previously but can anyone tell me if the wastegate could cause have somehow caused it? Also feel like I might be on for a major breakdown in the near future with the wastegate issue.

This is my first turbocharged engine and first volvo and even though its going like a rocket now (still needs maf) I dont know enough to say how or why this problem came about or if its still something I should be worried about.

Has anyone else had these issues and had any more problems if fixed in a similar way?

[abscate]

Was the rattle rpm dependent or constant ? Can you describe the frequency (knock like on wood, nuts in a can, pilested woodpecker on tree trunk) too to help narrow down? Was it constant frequency or varying ?

[belskee]

The rattle did increase/decrease with the revs, after 2500 would disappear, the rattle itself was hard to describe but did have a distinct metallic sound almost like failing tappets but alot more aggressive (closest would be your nuts in a can).

When the car warmed up it was quieter until reved but at that point became random ie. Sometimes you rev and made the rattle as revs increased sometime you rev but rattle would occur as revs decrease.



Prodding the turbo heat sheild made no affect on the frequency

[vtl]

My guess is T-belt was incorrectly installed. I had pretty much same rattle when I spilled some Pentosin over serpentine belt and did not clean it properly, the belt soon became shredded in zillion pieces, one of kevlar fibers got under crank and T-belt skipped one tooth on exhaust.

T-belt change is difficult in this car, unless you know how to make it easy with the paper clips and white corrector marks on belt/pulleys.

[belskee]

Well I haft to disagree there, the rattle was fixed without touching the belt so if my timing is out I'd still have the rattle, it was either the heat sheild or the wastegate as those were the particular components that I played with that stopped the rattle, my intension of this post was to decipher whether or not the wastegate could possibly cause a rattle due to it being siezed shut.

Ive replaced the belt pulleys and pump on this car few months back and with the help of the guys on here I didn't have any problems whatsoever, infact it was probably the easiest belts I've changed, compared to a golf where you have an engine mount to remove with no room to work with and requires supporting the block just to change a belt (needless to say im never buying a golf -.-) but yeah v70 was much easier.

[abscate]

The wastegate noise on my turbo is a soft wish wish wish, definitely nota rattle.

My VW turbo is definitely a flutter rattle.

Both of these are brief, just a second or so, when you lift.

[belskee]

Yeah so was more likely just the heat sheild then, do you think my wastgate is going to be alright? Not had any issues since the hammer treatment but did take alot of hardish hits to get it unsiezed, I know if it does fail its either a rebuild or replacement but being my first turbocharger im unsure as too how hard wearing they are.

Been told by a friend its not going to last much longer but that same person was positive I had a head gasket failier due to misting of antifreeze on the wndscreen, I knew he was wrong after reading on here about the o rings in the heater matrix and the emissions test for the mot showed good combustion, changed the rings and was fine.

needless to say the experience you guys have with these cars is alot more than his so I always listen to you boys instead, after the repairs ive made with the help offered on this site I'd advise anyone to do the same also.

[abscate]

The turbos on these cars are pretty tough. You might want to add a drop of oil to the wastegate pivot once a month to stop it from seizing again. I think the shield caused your rattle and you put it right.

Nattering nabobs of negativism are not helpful working on your car.