hadyn Posted August 8, 2007 Share Posted August 8, 2007 Just recently Ive noticed that my car feels a lot more sluggish on boost (j spec tt auto, standard) and is produces about 0.1 bar less boost than it usually does with both blowers on. The kick at 4k rpm is also less pronounced too. Ive also noticed a slightly different exhaust note with the first blower on, although sometimes it sounds as it usually does. There is no smoke on boost when I look behind me. What do you think is causing this? Vacuum pipe or vsv valve thingy ma jig? Ive had a minor issue whereby my second turbo sometimes doesnt come on when I plant it for kickdown and I believe this to be a dodgy VSV somewhere. If it were dying turbos, surely you'd get smoke and produce very little if any boost??? Car has now done circa 125k miles... Link to comment Share on other sites More sharing options...
Pig Posted August 8, 2007 Share Posted August 8, 2007 Could it not be related to the hot weather? Link to comment Share on other sites More sharing options...
gaz1 Posted August 8, 2007 Share Posted August 8, 2007 Could it not be related to the hot weather? it could indeed young buck:p Link to comment Share on other sites More sharing options...
hadyn Posted August 8, 2007 Author Share Posted August 8, 2007 Could it not be related to the hot weather? Nah its a bit more severe than the usual 'mild' drop in performance you get with hot weather every year. Also every time you start the car with the engine hot the car idles erratically for about 10-20 seconds bouncing between just under 1k rpm and 500ish rpm. Very strange Link to comment Share on other sites More sharing options...
Pig Posted August 8, 2007 Share Posted August 8, 2007 I would go with resest ECU, check all boost pipes. Only trouble is i have no technical knowledge Link to comment Share on other sites More sharing options...
hadyn Posted August 8, 2007 Author Share Posted August 8, 2007 Ive check the pipes around the visible turbo area, all seem sound apart from one, which appears to have a graze mark/hole in it at the back going to the rear of the engine. Dunno if its a full bore hole as I dont want to try and remove it just yet as Im worried of it disintegrating if I try to move it. Just wrapped it up in tape Link to comment Share on other sites More sharing options...
hadyn Posted August 8, 2007 Author Share Posted August 8, 2007 and bump Link to comment Share on other sites More sharing options...
hadyn Posted August 8, 2007 Author Share Posted August 8, 2007 Just had a look in the FAQ area and its the pipe labelled 'To pressure tank' that has the suspect crack/hole in it. Would a hole in this pipe to the pressure tank cause the above problems? Link to comment Share on other sites More sharing options...
Ric Posted August 8, 2007 Share Posted August 8, 2007 if there is a leak to the pressure tank it means the vsvs wont be getting enough pressure through the hoses to operate properly. 0.1 bar is 100% heat/weather related, i get 1.1 in the day 1.25 in the cooler evenings Link to comment Share on other sites More sharing options...
hadyn Posted August 8, 2007 Author Share Posted August 8, 2007 if there is a leak to the pressure tank it means the vsvs wont be getting enough pressure through the hoses to operate properly. Which would cause turbo number 2 not to come online when I kickdown at 60mph + sometimes? Link to comment Share on other sites More sharing options...
hadyn Posted August 8, 2007 Author Share Posted August 8, 2007 I also take on board the heat could be causing the slight drop in pressure with both blowers on, but it sometimes has been feeling rough/choppy when on boost and what does the change in exhaust note mean? Would all that be hose/heat related too? Link to comment Share on other sites More sharing options...
Pig Posted August 9, 2007 Share Posted August 9, 2007 Which would cause turbo number 2 not to come online when I kickdown at 60mph + sometimes? This is almost def. the VSV's or actuator - the bit that switches to the second turbo. Its getting more common for it to happen on the cars and IIRC is a reasonable size job to replace. It took till my turbo's were off for mark at pheonix to work out why this was happening to my car. Bad news for you, it will happen more and more Link to comment Share on other sites More sharing options...
redtwinturbo Posted August 9, 2007 Share Posted August 9, 2007 On the heat related note - whats the condition of your Intercooler like? Are you still running stock? Link to comment Share on other sites More sharing options...
hadyn Posted August 9, 2007 Author Share Posted August 9, 2007 Intercooler is a stock Miami GT replacement SMIC in great condition The hole i believe is in the pipe to the pressure tank. I read in a thread elsewhere that CW stated he had never seen a failed pressure tank on any car he had worked on. Alls I have to do is replace the pipe surely? Link to comment Share on other sites More sharing options...
Fifty Posted August 9, 2007 Share Posted August 9, 2007 Which would cause turbo number 2 not to come online when I kickdown at 60mph + sometimes? kickdown positively sometimes if youve just not been aggressive it will do this. 2 turbo comes on at 4000 rpm for me. Try dropping out of overdrive as well first Rich Link to comment Share on other sites More sharing options...
hadyn Posted August 12, 2007 Author Share Posted August 12, 2007 Quick update. Ive replaced the rubber hose that goes to the metal pipe to the pressure tank. The old hose I removed literally crumbled apart when I tried to take it off. Plus it seemed to have a hairline crack in it. I havent had chance to test what its like with both turbos online, but it does seem a bit punchier on the 1st turbo at lower speeds. Ill report back tommorow when I've had a chance to boot it Link to comment Share on other sites More sharing options...
hadyn Posted August 15, 2007 Author Share Posted August 15, 2007 OK. The car is boosting as it should from low speeds, low revs. However when I floor it/kickdown on the roll at about 50-60 mph I get my boost gauge showing 0 bar boost and I dont seem to be making any boost at all Any ideas what this is? Is it one of the VSVs? EGCV??? Link to comment Share on other sites More sharing options...
hadyn Posted October 19, 2007 Author Share Posted October 19, 2007 OK. The car is boosting as it should from low speeds, low revs. However when I floor it/kickdown on the roll at about 50-60 mph I get my boost gauge showing 0 bar boost and I dont seem to be making any boost at all Any ideas what this is? Is it one of the VSVs? EGCV??? Quick bump of this thread to see if anyone knows what may have caused this? Link to comment Share on other sites More sharing options...
colsoop Posted October 20, 2007 Share Posted October 20, 2007 Do you have another boost gauge to try just to rule that out ? Link to comment Share on other sites More sharing options...
RedM Posted October 20, 2007 Share Posted October 20, 2007 Question: If your revs went up but the car didn't go anywhere, as in a slipping clutch etc would you still get boost? Link to comment Share on other sites More sharing options...
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