Engine or Transmission failing
Engine or Transmission failing
I have the Procharger installed on my 2003 A/T coupe and I am losing power everytime I have the vehicle dynoed. In August my hp was 350, in October my hp was 335 and in December my hp was 324. I noticed at 60mph my rpms are at 2000, while my (Saturn Vue) winter vehicle at 70mph the rpms are at 2000. Is my engine starting to go or is my transmission starting go? The transmission hesitates shifting from 1st to 2nd gear.
well, regarding the RPM comparison to the Saturn Vue, it has no bearing whatsoever since the two vehicles use completely different gearing and different gear ratios
as for the 5AT.... have you done work to the transmission to allow it to handle the extra power? most people who run FI on a 5AT at least get a valve body upgrade (to allow the tranny to shift more positively and hold the power without overheating) and possibly a higher stall speed torque converter.
EDIT: a tranny cooler will help to keep the transmission fluid from overheating also due to the added stress
as for the 5AT.... have you done work to the transmission to allow it to handle the extra power? most people who run FI on a 5AT at least get a valve body upgrade (to allow the tranny to shift more positively and hold the power without overheating) and possibly a higher stall speed torque converter.
EDIT: a tranny cooler will help to keep the transmission fluid from overheating also due to the added stress
Last edited by SI_G35Coupe; Dec 17, 2005 at 03:35 AM.
I have added a transmission cooler and have the level 10 valve body upgrade and those things did not help with the shifting. I have not added a torque converter. Would that help or is there a way to adjust the valve body? How would you explain the loss in torque & hp after every dyno 3 separate times?
Thanks for your response.
Thanks for your response.
hmmmm. where in NY are you located? if you're close to NJ you might want to get in touch with MRC Motorsports, they may be able to check the whole car over and see if something is amiss
With the Procharger I would definately get a compression check IF you think there may be motor problems. If not tuned perfectly the Procharger (and any other form of supercharger) can easily crack piston rings. The car will still run great, but you'll lose compression, and thus HP will drop off.
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first thing first do a compression test. After you do that, do a leak down test as well.
Check all your belts to see if any of them are slipping.
if you had engine issue it would have been missed. When you do a dyno, what is your A/f ratio? Check your plugs also see how they are?
tranny could be a possibility, but you would have seen more signs such as slipage or jerking between shifts
Check all your belts to see if any of them are slipping.
if you had engine issue it would have been missed. When you do a dyno, what is your A/f ratio? Check your plugs also see how they are?
tranny could be a possibility, but you would have seen more signs such as slipage or jerking between shifts
Originally Posted by myGspot
first thing first do a compression test. After you do that, do a leak down test as well.
Check all your belts to see if any of them are slipping.
if you had engine issue it would have been missed. When you do a dyno, what is your A/f ratio? Check your plugs also see how they are?
tranny could be a possibility, but you would have seen more signs such as slipage or jerking between shifts
Check all your belts to see if any of them are slipping.
if you had engine issue it would have been missed. When you do a dyno, what is your A/f ratio? Check your plugs also see how they are?
tranny could be a possibility, but you would have seen more signs such as slipage or jerking between shifts
To answer Booger & MyGspot questions I am using the Emanage to tune the car and my A/F ratio is 12/1 according to the dyno. However according to my AEM wideband gauge it is around 15/1 to 16/1. I changed the plugs about 4000 miles ago to Iridium cold spark plugs. It feels like there is not enough air getting to the engine when shfting from 1st to 2nd and 2nd to 3rd. I had the TPS checked by the dealer and by another mechanic and it checked out fine. Does anyone have a mapping of what the settings should be using the Emanage to tune our vehicles?
if the wideband is showing the 15/1 then i would start there first. seems like something is not right.
Why would there be such a huge difference between dyno and aem? may be 1 but not 4
also i was never a fan of level 10 because i heard a lot of bad stories of guys who used them. Protorque is out on LI and they are very good. couple of my friends used them.
Why would there be such a huge difference between dyno and aem? may be 1 but not 4
also i was never a fan of level 10 because i heard a lot of bad stories of guys who used them. Protorque is out on LI and they are very good. couple of my friends used them.
Originally Posted by myGspot
if the wideband is showing the 15/1 then i would start there first. seems like something is not right.
At 15-1 or 16-1 under boost you are running too lean and it is potentially dangerous to the engine... those are exact conditions for detonation and blowing your engine.
I would always trust an in car O2 over a dyno O2. Leaded race fuels will destroy an O2, and most dynos are located in the cleanest of facilities. Unless you know for a fact that the dyno's O2 is in good working order and taken well care of I wouldn't trust it at all!
I had the compression test peformed on the vehicle and they told it was 120 across the board and I should tell the tuner those numbers the next time I have the vehicle tune. If the engine is fine what else could be causing me to lose power? Maybe the tune is not correct? I need help on this matter.
