1998 t4 issues

[dizzledrift]

Hey,
i have recentely purchased my fathers 1998 s40 t4 which he owned from 1999 on 16,000 miles, she now has 74,000 and has been well looked after mechanically few scratches down one side but a bit of tlc and should be fine. I have a few issues and was wondering if anyone can point me in the right direction.

1. Not always but sometimes in 3rd, 4th and 5th gear around 4,000 rpm the engine holds back wont go past 110 mph in 4th but sometimes is fine, having read the forum i suspect lamba sensor since the light came on a then a day later reset itself.

2. Since my father owned the car it has had a knocking from the front suspension i think drivers side, sounds like a shock absorber but has been changed and still persists, has been looked at a few times but no problems were found...

3. Every time you decelerate it has an annoying rattle i reackon the actuator arm after a bit of reading though, is this an easy job? seems hard to get to after fitting a dump valve.

4. I fitted a forge motorsport dv which is fine but when i was dismantelling the air box i broke the little pipe which attaches to the induction hose just after the airbox and was wondering if the is a cheaper option rather than the £60 volvo want for the hose?

any help welcomed
thanks
Ian

[T5frankie]

It seems every t4 has the same suspension problems mine has it too and is probably the ball joint, as for the speed isue do you put 98 octane petrol in cos on my fuel cap its says 98 only if you are using 95 petrol this could cause such problems

[gmain1967]

The rattle on deceleration could well be the wastegate arm. Or, it could be the heatshields (around the turbo), or even on the exhaust.

Given that you will have to remove the heatshields to gain access to the wastegate actuator and adjustment, you can check for both at the same time.

Personally, I would remove the heatshields, then take it out for a run and see if that has remedied it. Prior to that, check the wastegate arm for movement and wear (the hole in the adjuster wears oval). If there is slack on the arm, slacken off the 10mm lock nut, and turn the arm towards the nut once more, after removing the r clip. Only do a turn at a time, and try it out.

Ideally, you only want to adjust the arm if you have a boost gauge, as tightening the arm (shortening it), will result in higher boost. If you do not have a gauge, only adjust it enough to take up the slack.

Cheers

[dizzledrift]

It seems every t4 has the same suspension problems mine has it too and is probably the ball joint, as for the spped isue do you put 98 octane petrol in cos on my fuel cap its says 98 only if you are using 95 petrol this could cause such problems


Yes i am using optimax 98 in her, have been for a few months now seems the same though, will have a good look at the ball joint over the weekend. thanks for the pointers mate

[dizzledrift]

The rattle on deceleration could well be the wastegate arm. Or, it could be the heatshields (around the turbo), or even on the exhaust.

Given that you will have to remove the heatshields to gain access to the wastegate actuator and adjustment, you can check for both at the same time.

Personally, I would remove the heatshields, then take it out for a run and see if that has remedied it. Prior to that, check the wastegate arm for movement and wear (the hole in the adjuster wears oval). If there is slack on the arm, slacken off the 10mm lock nut, and turn the arm towards the nut once more, after removing the r clip. Only do a turn at a time, and try it out.

Ideally, you only want to adjust the arm if you have a boost gauge, as tightening the arm (shortening it), will result in higher boost. If you do not have a gauge, only adjust it enough to take up the slack.

Cheers



Thanks for the point in the right direction mate im 99% sure the the actuator arm now, havent looked at tighting it yet though. service light now on so might get them to do it whilst its in. thanks again.

[The-Les]

I have the same problem, changed all leads, ignition coils, plugs, front lambaba sensor, air filter. I found that number 4 plug gets oiled up after a while and cleaning it makes a bit of a difference, so I'm thinking it could be a PCV valve clean up or valve stem oil seal. got a sports cat coming soon that should help a bit. also did what gmain said in the wastegate arm that worked a treat on the rattle.

[dizzledrift]

I plugged my t4 into a mates diagnostic thing the other day and its showing a fault on the crankshaft position sensor(p0355) and a lamda sensor fault (bank 1 sense 2 high voltage) not sure which sensor this is the pre cat or after cat?

[The-Les]

I have the same problem, changed all leads, ignition coils, plugs, front lambaba sensor, air filter. I found that number 4 plug gets oiled up after a while and cleaning it makes a bit of a difference, so I'm thinking it could be a PCV valve clean up or valve stem oil seal. got a sports cat coming soon that should help a bit. also did what gmain said in the wastegate arm that worked a treat on the rattle.

just spent 4 days replacing the valve stem oil seals and cleaning the head, new gasket, valve regrind and the like. found one of the oil seals had lost it's retaining spring. now runs very very sweet. well worth the effort.