T5 Screaming/Blowing sound - AGAIN!

[SonyVaio]

Hi all,

Yesterday I started the car to met with a screaming sound and what also sounds like a whole in the exhaust. Now as I've had a similar problem in the past I kind of new straight away where the problem lay, even though Volvo were supposed to have sorted it 9 months ago!

Long story short the manifold bolts (manifold to engine bolts) had come loose, AGAIN!

LINKY! to a post I made at the time.

LINKY! to a post where T5Monkey had the same problem - TWICE!

LINKY! to where Johandh also experienced the exact same problem too. In another T5!!

So it appears that there is a bit of a trend here in that the manifold bolts on these S40/V50 T5 engine cars are working themselves loose every now and again.

I've done a good 20,000 miles since mine were last tightened by Volvo and supposedly properly torqued but they have come loose in a mere 9 months.

Today I set about the task of tightening the manifold bolts myself - what a nightmare I had, so much can be said for a proper ramp and equipment on hand, but thankfully all done and everything back together again.

Process:

• Jack up car
• Place on axel stands
• Remove OEM strut brace
• Remove air inlet pipe to turbo (long plastic one)
• Remove engine under tray
• Remove air inlet pipe to turbo (short rubber/flexi one from top to bottom of engine), had to get to bottom jubilee clip from underneath
• Remove 3 x bolts to heat shield (used missus vanity mirror to locate) - dropped one 'bugger no idea where it went'
• Check/Tighten all 8 manifold bolts (used missus vanity mirror to locate) a couple of these bolts are a little hard to reach but manageable

Put everything back together in reverse order (after finding dropped bolt) and start the car......Yippee, all quiet again. I was very surprised, there was 4 bolts that were loose and required tightening, this was the 4 manifold bolts on the drivers side (off side) of the car. There was one of the very outer off side manifold bolts so loose I'm surprised it was still on at all, without the ratchet attached I was able to get the socket with a short extension on and turn the bolt with my fingers a good 4 or 5 turns, this turned out to be one of the hardest to locate bolts too so I'm truly wondering if Volvo even tightened this one the last time.

Well all done now anyway but certainly something for you T5 owners to be aware of. It has happened to few people and all with the T5 engine.

If they come loose again then they are going to get new bolts and Loctite to the death!

[gswede]

Good post, some nice albeit scary information there.. :-)

Had a screaming sound myself a couple of years back, related to exchaust. Brought it in to volvo, on the hoist we could see 2 of 3 blots holding the downpipe missing..! You heard me right, the downpipe was held in by 1 bolt.
Everytime I am under the car, i check to see if they are all in place.

Got another squeel at the moment though, the PCV howl. Actuall it is not the PCV howling, it comes from the seals sucking in air under vacuum.
Squeel goes away if I take the dipstick out.
New PVC on order from fcpgroton. Only 120USD.

Price for same unit in norway, 530USD - crazy!

[johandh]

Great post sony

It seems to be a real common problem on the S40, had the same issue with my T4, 2x2.0T and my T5 as you know. Seems to be mostly on the same side that the turbo bolts the the manifold.

Johan

[craigblues]

Sounds like a common problem but a problem that shouldn't be there.

Nice in-depth post. :-)

[Daim]

@ Sony

Does the T5 have studs or bolts? My older Volvos with the modular engine (whiteblock -> T5 is a family member) had studs and they would loosen very easily... You can't overtorque them, as they are fixed to the alloy head. Torque them higher, and you'll ruin the alloy head...

[SonyVaio]

Daim, I agree over torqueing is not a good thing but Volvo go for a standard torque setting for certain bolt size. The manifold bolts are M8 and the torque setting is a mere 24Nm. Now I think that torque setting may be on the low side and perhaps half the reason the bolts come loose??

Studs: There are studs that go into the block and then bolts screw on to the studs and keep the manifold in place. Just to correct my original post it supposed to read 'Check/Tighten all M8 manifold bolts' as there is more than just 8 of them.

I think it is probably worth using Loctite (strong one) and torqueing up the bolts to standard torque.

[RiPsTa33]

Originally Posted by SonyVaio

Daim, I agree over torqueing is not a good thing but Volvo go for a standard torque setting for certain bolt size. The manifold bolts are M8 and the torque setting is a mere 24Nm. Now I think that torque setting may be on the low side and perhaps half the reason the bolts come loose??

Studs: There are studs that go into the block and then bolts screw on to the studs and keep the manifold in place. Just to correct my original post it supposed to read 'Check/Tighten all M8 manifold bolts' as there is more than just 8 of them.

I think it is probably worth using Loctite (strong one) and torqueing up the bolts to standard torque.

Did you mean nuts screw onto the studs

[Daim]

I was going to ask if you had used loctite (heat proof!) yet... Do you need nuts for the same job? If so, tried self locking nuts? That should do the job... In the end, I fitted new longer studs to the 6 cylinder engine. The studs had loctite so they stayed put in the head. The nuts then were torqued to the right spec and then a second nut was put on the end and tightend against the standard nut. Result: didn't undo itself anymore...

[SonyVaio]

Originally Posted by RiPsTa33

Did you mean nuts screw onto the studs

Yes, yes I did mean a nut.

@ Daim

Unfortunately I didn't have any Loctite to hand but if it comes loose again I will definitely get new studs and nuts and then ensure they are well loctited in.

Not a bad idea with extended length studs and an extra nut. Will see how it goes for now but watch this space in probably another 9 months. Although my mileage will drop considerably from now to approx. half of what I have been doing so it may be 18 months.

[v70stu]

Sorry to drag this up. I've now got the same issue. I've checked the 3 bolts on the downpipe to turbo joint and they are fine so I am left with manifold bolts. What I have discovered, having looked at it tonight is - how the he'll do I reach these chuffing bolts?! Any special tools required? Any tips? If I leave it to the garage, how long should it take them so I can work out a cost? Thanks!