Hey all,

I posted a problem up a few weeks ago here http://www.volvo-forums.com/t14894--limp-mode-33.htm and I would just like to thank those that replied. I have been away on business a lot the last few weeks so apologies if I didn't thank you earlier.

I thought I would update you on this issue as I am finding it to be rather unique and complicated and I post in the vain hope that again, someone might have some good advice for me to try.

Initial Problem
When driven at high(ish) speed my car would occasionally suddenly reduce its power from 260BHP to around 100/150BHP. Without warning it would suddenly return to normal again.

First action
Took to local independent dealer who spent 3-4 hours examining the car. VIDA stated "boost pressure too high" in regard to the turbo system, so this area became the focus. Upon examination they found one of my "air charge" (?) pipes to have a hole/split in it. This was, speculatively, the cause of my woes so it was changed.

Result
I picked up the car yesterday post-repair and within 30 seconds of leaving the garage, the car spluttered and immediately read "Reduced Engine Performance" in the messages screen on the dash. The car had reentered "limp mode" again and was back to being 100/150BHP only this time the car was showing a proper and permanent error code.

I took it straight back to the garage for a look. VIDA reported, again, "boost pressure too high". I must admit, after the split pipe was changed, the car did feel a bit faster and pokier than before. The engineer thinks however that the car did feel like it was boosting too hard.

Speculation/ideas
Here are a few comments that were made to me at the garage;

• Car potentially has been re-mapped in the past and done badly, thus leaving the engine in a state of over-boosting. The split pipe I had allowed enough pressure to escape leaving the car in a somewhat normal state. Having repaired the pipe all pressure is restored, and its just too high.

• Engineer noticed one of my turbo air hoses was slightly too supple. He thinks that upon the turbo sucking through air, this pipe might collapse in on itself, a la vacuum effect, causing no air to enter turbo... turbo cuts... engine reduces etc...

• A.N. Other problem yet to be discovered.

To change the pipe as mentioned above has so far cost £300/$600, and based on the fact its actually now made my problem worse, I will potentially have to pay another £300-500/$600-1000 in further examination/diagnostic fees PLUS the actual repair costs should they find whats wrong! This is gonna screw me for weeks! And the car is only 2.5 years old! :(

Therefore I plead with anyone out there to let me know if they have ever experienced "over boosting" problems with an S60 T5, and what you learned from it.

Could it just be a sensor? You might think that the pipe would not have split in the first place if the boost pressure was really ok!?

Thank you in advance for any further help!

Regards,

Frontman.

Just to let you know, the problem is now fixed. Turns out the turbo vacuum pipe was trapped under a filter, blocking the pipe almost closed. This caused an over boost problem and threw the car into limp mode. The pipe was released, and renewed, now the car is 100% fit. This was as a result of work done by/for the previous owner. What they were doing there on a 1-2 year old car, I don't know.

Just thought I'd share in case anyone else ever searches this topic.

Ah yes, they were probably one of these people you see around here trying to "Tune" the car for some extra kick. Maybe it's snobby of me but I do have a tendency to snicker at these folks.

My thoughts are that these cars are HIGHLY engineered. That parts are designed specifically to work with other parts, that assumptions were made during the engineering process about the performance and power of the engine and that this is a delicate ecosystem that shouldn't be messed with without serious know-how and even then you take-on some risk.

If you're one that likes to tinker, well, my thoughts are: Go buy yourself a car from the 60's or 70s.

Of course, you own it. You can do what you want. But don't be surprised when stuff like this happens to your car.

It just sucks for the rest of us who buy these things without being told that the previous owner tried to play Race Car with it.

on the one hand i agree with you, if you don't know what you are doing, leave it alone. but, and there is always a but, for people who do know what they are doing, the potential to improve on what the engineers wanted and what was produced, is too great a temptation. why did you pruchase the Turbo, should have gone for the plain jane s40, it is safer that way. any business person who has had to deal with management will understand my next statement: bean counters are known to make sure that the product that is being produced will have the widest appeal possible, otherwise the product will only be bought by a niche market. hence the R designation on the volvos. m on the bmw. amg, mercedes, svt, ford, ss, chevy, etc. etc. now, even these niche cars, they have to be mass produced, to a point, to be economically viable. the factory isn't producing cars for 2 guys in sweden who want 400 horsepower. but there are 1000 guys around the world who will buy one with 300 horsepower. now if you know the car is capable of handling 400 horsepower, wouldn't you want to get it back? of course, otherwise you would be driving a toyota. and don't give me the safe car arguement, safe or not, speed doesn't kill, it is the ineptness and the unforseen circumstances that causes the accidents. driver error, drinking, etc. the first fatality in new york was in the early 1900 and the car was traveling at 12 miles per hour and hit a lamppost. 12 miles per hour. my wife bikes faster than that. so, your answer is correct to a point. but the real point is, if you want to do something right, pay for an expert. sorry for jumping on my soapbox, but if you look at my cars, you will see that i am not talking out of the side of my mouth. i am 40 years old, enjoy my toys, race on a track, have been known to rip a good burnout done the front of my block. i am a responsible adult, an upstanding member of the community, and a respected businessman. i could drive whatever i want, hence the wifes mercedes. i choose to burn rubber, and i am happy to have the choice and the know how on how to achieve it. and if i don't know what i am doing, i get the right mechanics who do. thanks.