Several issues i would appreciate opinions on.

[boosted3]

I know this is a longwinded message but i decided I would cram it all into one post and hope some fellow Buick owners would chime in and help me out. I just bought this car and am a little worried about some of the issues it has.

First is the engine noise. The car has excellent oil pressure, at operating temps of 185 with 15-20 psi at idle and 50-60 psi at a 50mph cruise. I dont know much about the engine other than it was rebuilt about 10 years ago. it has an aftermarket 210/205 cam (not sure what manuf). The sound is almost non existent when cold and slowly gets louder as the car warms up to operating temps. It increases in sound level and speed as the car increases in RPMs so much that i can hear it from inside the car over the sounds of the exhaust.(full exhaust without muffler or cat with stock DP.) It sounds like rocker noise but it has stock rocker shafts in it. The car has 189,000 miles on it. Can the rocker shafts wear out causing noise, or is it possible that is has the noisy clicking comp cams lifters i have been reading about???

Second is cold idle. The car had a bad MAF sensor and would not idle cold. I tested by disconnecting the sensor at idle and the idle smoothed out. Today i replaced it with a known good sensor purchased on the board, reset the computer and took it for a cruise of around 15 miles. The car ran great and the O2s were back up to decent numbers at idle with no more MAL codes. The car has a heated O2 sensor in it that did throw a code but i have not replaced it yet. tonight after work i fired the car up and it would not idle again. It did not throw a code but while it was idling the O2s were cycling down below 100. I held the car at about 2000 rpms to warm up and when i let off it took a second searching and then smoothed right out idling and O2s increased to cycle up into the 6-700s and drove fine after. is this an effect of the bad O2 sensor or possibly a vacuum leak?

Third is the temp readings im getting. The car is equipped with a scanmaster and an AutoMeter Sport comp mechanical temp gauge. The scanmaster reads approximately 10-15 degrees cooler then the gauge. Are there 2 different points temps can be read from and if so which one should i go by?

Fourth is the Air Temperature sensor. All of the ATS i have seen are in the MAF pipe before the turbo. This car has the sensor installed into the up pipe coming off of the FMIC right before the throttle body. Is this a normal thing or should this sensor be moved back to the stock location?

Lastly is the transmission. It feels like it has a shift kit, i know it has a stage right transbrake and a 3000 stall non lockup converter. Tonight i took it for a ride and the shift 1-2 was crisp along with 2-3. It seems however to search for overdrive sometimes while driving and wants to downshift very easily. Earlier i drove it and it was searching so quickly it felt like a miss in the engine. Then tonight at one point it banged into overdrive at a 55 mph cruise. the shift was so hard it felt like the trans was going to jump out of the car. That was the only time it has done that in the 5 days I have had the car.

I hope to look into some of these problems myself but unfortunately i work 14 hours a day 7 days a week at my restaurant and only have about 2 hours at night to drive the car so i am relying on the wealth of knowledge on this board to help me out and try to narrow my options down so with the little bit of time I have each day, i can look at more specific things rather than wasting time chasing something i do not need to.

Aside of these issues the car runs great! It pulls very strong, shifts well under power, and at 15 psi boost, has no KR at 42 psi fuel pressure. I will add that I live at 4,500ft of elevation and only have 91 octane at my disposal.


Thank you very much for any help you can give me!!!!

I went out and took some SM readings to help. Im sure the neighbors loved that at 12:45 at night!

CLT - 180
O2s - 100-700 cycling at about 2 sec intervals
AF - 05 steady
L8 - 35-39
bat - 13.7
INT - started at 142-149 and dropped to 120-130 as it warmed up
bl - 135
ATS - 91
RPM - 775
TPS - .48
IAC - 09-11
cc - 11-249 steady climb through the range and then back to beginning.

Thanks again for even reading this far!!!

 

[TurboBuRick]

First is the engine noise. The car has excellent oil pressure, at operating temps of 185 with 15-20 psi at idle and 50-60 psi at a 50mph cruise. I dont know much about the engine other than it was rebuilt about 10 years ago. it has an aftermarket 210/205 cam (not sure what manuf). The sound is almost non existent when cold and slowly gets louder as the car warms up to operating temps. It increases in sound level and speed as the car increases in RPMs so much that i can hear it from inside the car over the sounds of the exhaust.(full exhaust without muffler or cat with stock DP.) It sounds like rocker noise but it has stock rocker shafts in it. The car has 189,000 miles on it. Can the rocker shafts wear out causing noise, or is it possible that is has the noisy clicking comp cams lifters i have been reading about???

Hard to say over the net. What kind of rockers? Stock?

Second is cold idle. The car had a bad MAF sensor and would not idle cold. I tested by disconnecting the sensor at idle and the idle smoothed out. Today i replaced it with a known good sensor purchased on the board, reset the computer and took it for a cruise of around 15 miles. The car ran great and the O2s were back up to decent numbers at idle with no more MAL codes. The car has a heated O2 sensor in it that did throw a code but i have not replaced it yet. tonight after work i fired the car up and it would not idle again. It did not throw a code but while it was idling the O2s were cycling down below 100. I held the car at about 2000 rpms to warm up and when i let off it took a second searching and then smoothed right out idling and O2s increased to cycle up into the 6-700s and drove fine after. is this an effect of the bad O2 sensor or possibly a vacuum leak?

O2 sensor has nothing to do with cold idle. Looking at your sm #'s, your tps needs to be .42. Did you play with the throttle plate screw? That should never be touched. Back the screw out till tps reads .42. Once set, get the IAC # warm at idle.

Third is the temp readings im getting. The car is equipped with a scanmaster and an AutoMeter Sport comp mechanical temp gauge. The scanmaster reads approximately 10-15 degrees cooler then the gauge. Are there 2 different points temps can be read from and if so which one should i go by?

That's not unusual. Go off the scanmaster. Once you know the spread, you still use the gauge for reference.

Fourth is the Air Temperature sensor. All of the ATS i have seen are in the MAF pipe before the turbo. This car has the sensor installed into the up pipe coming off of the FMIC right before the throttle body. Is this a normal thing or should this sensor be moved back to the stock location?

If your running a maf then it should be in the air filter flange.

Lastly is the transmission. It feels like it has a shift kit, i know it has a stage right transbrake and a 3000 stall non lockup converter. Tonight i took it for a ride and the shift 1-2 was crisp along with 2-3. It seems however to search for overdrive sometimes while driving and wants to downshift very easily. Earlier i drove it and it was searching so quickly it felt like a miss in the engine. Then tonight at one point it banged into overdrive at a 55 mph cruise. the shift was so hard it felt like the trans was going to jump out of the car. That was the only time it has done that in the 5 days I have had the car.

The tv cable has been set for performance. You could let out a notch or 2 and that will help around town shifting.

 

[boosted3]

Hard to say over the net. What kind of rockers? Stock?




O2 sensor has nothing to do with cold idle. Looking at your sm #'s, your tps needs to be .42. Did you play with the throttle plate screw? That should never be touched. Back the screw out till tps reads .42. Once set, get the IAC # warm at idle.



That's not unusual. Go off the scanmaster. Once you know the spread, you still use the gauge for reference.



If your running a maf then it should be in the air filter flange.




The tv cable has been set for performance. You could let out a notch or 2 and that will help around town shifting.

The rockers are stock from what i can see by taking off the oil filler cap.
I did not touch the throttle plate screw. the numbers are exactly what they have been since i have had the car.
Thanks! I will work on the TPS setting this morning and try to get a new number.
Being that it is saturday I may be able to try to tweak some things on the car throughout the day so if someone sees something that i may be able to work on and post a new result, let me know and i will do my best to get the numbers up. Thanks for the help!

 

[HIboostGN]

The noise might be and I MEAN MIGHT BE a rod bearing letting go. If the noise follows rpm then that is usually the case. You might have lost a rod bearing with severe det or bad build from before? It also could be a rocker shaft or rocker. Pull the valve covers off and check all rockers and shafts to make sure the shafts haven't broke or cracked and that all the rockers move freely when not on the lobe. It also could be a lose timing chain which is slapping around if someone put billet caps on there and did not get the correct shorter chain and just installed a stock chain size it will get sloppy real fast and could cause noise after many many miles? First thing check rockers and shafts! You could get a stethoscope and listen to where the noise is really coming from and that will lead you to the problem a lot easier then long distance or over the web. I feel for you my DD driver has a bad rod bearing i killed it with to much timing and a race with a Porsche!

 

[boosted3]

Im almost positive that it is not a rod. I have spun a rod bearing and wasted a buick engine before and unfortunately know what it sounds like. I think if i had to put my money on something i would go with lifter, rockers, or timing set. If it is the timing set making noise would oil temp affect it? because the sound is non existent when the car is cold making 70psi of oil pressure and i dont really start to hear it til the oil pressure gets under 30psi. and it sounds like the majority of the sound is coming from the passenger side up high. there is a little noise on the drivers side but the loudest is passenger.
Thanks guys!!!

 

[boosted3]

Update

Well i took the car for another ride tonight to try to get closer to the cause. The noise is only heard inside the car when i am under hard acceleration. The only time i can hear the sound at idle is when i am under the hood. So the noise increases with RPM and is at its loudest under a heavy load. It seems to me it could either be a rocker shaft or the timing set but I would like to hear what someone else thinks! The car idled fine this morning and this evening so I am hoping that the idle problem could have just been the computer relearning after i changed the MAF sensor and reset it.
Thanks for your help!!

 

[HIboostGN]

You could also check while the engine is running with the tranny shield off if it is the converter bolts. If you recently changed the converter or had the tranny out if they become lose they will sound like a rod knock also and follow rpm. I think today or soon you should pop the valve covers and make sure it is not a valvetrain problem then go from there. Guys are breaking the HD shafts with the RJC braces so don't think it might not be you too? SMILE

 

[boosted3]

Well like i said before. I have spun a rod bearing in a Buick before. I have been trying to think of something to compare the noise to but I have been pretty unsuccessful. The best way i can say it is the tone of the sound is usually directly related to the size of the part making the noise. A rod knock or wristpin knock is a lower tone because it is a bigger part. This is more of a tapping higher pitch almost like a hammer and chisel sound with metal against metal. I have narrowed the sound down to the passenger side valve cover. I work 14 hours a day 7 days a week so time is not on my side for getting to remove the valve cover to take a look. I thank all of you for your input and once i have time to remove the valve cover to take a look i will update my situation. Thanks!

 

[boosted3]

Well like i said before. I have spun a rod bearing in a Buick before. I have been trying to think of something to compare the noise to but I have been pretty unsuccessful. The best way i can say it is the tone of the sound is usually directly related to the size of the part making the noise. A rod knock or wristpin knock is a lower tone because it is a bigger part. This is more of a tapping higher pitch almost like a hammer and chisel sound with metal against metal. I have narrowed the sound down to the passenger side valve cover. I work 14 hours a day 7 days a week so time is not on my side for getting to remove the valve cover to take a look. I thank all of you for your input and once i have time to remove the valve cover to take a look i will update my situation. Thanks!

 

[Pronto]

Unfortunately you're going to have to pull that valve cover and pull the rocker shaft to check out everything. Hopefully it's something there on top. You're BL is high too. I see you've had the car only 5 days. It might do you well to the the "spring cleaning" and go from there. Check all your lines for a vacuum leak. Set your tps and iac.