P0507 code need help

[DavidT]

So I did a Gasket job on my 96 lesabre. It was all stock and factory until I worked on it. Now I’m getting a whistling squeal but when I remove oil stick it goes away. All gaskets are correct I changed almost every sensor / valves that could be the culprit still to no avail. I noticed where the gasket for throttle body to Intake manifold there are little circle grooves that stick out half of one circle is broken could that be the problem?

 

[DavidT]

So I did a Gasket job on my 96 lesabre. It was all stock and factory until I worked on it. Now I’m getting a whistling squeal but when I remove oil stick it goes away. All gaskets are correct I changed almost every sensor / valves that could be the culprit still to no avail. I noticed where the gasket for throttle body to Intake manifold there are little circle grooves that stick out half of one circle is broken could that be the problem?

 

[DavidT]

So I did a Gasket job on my 96 lesabre. It was all stock and factory until I worked on it. Now I’m getting a whistling squeal but when I remove oil stick it goes away. All gaskets are correct I changed almost every sensor / valves that could be the culprit still to no avail. I noticed where the gasket for throttle body to Intake manifold there are little circle grooves that stick out half of one circle is broken could that be the problem?

Help

 

[Tcapper]

Late reply, but I'm not exactly sure how the gasket routes but if that is part of sealing the throttle body, it could definitely be causing a vacuum issue (noise, possible codes). A couple of ways you could check where the leak is, is by using a smoke machine, a very useful tool or using a mechanics stethoscope to listen for the noise. Just looking at the picture, it looks like somebody used RTV silicone to try to seal something? Removing the oil dipstick is for lack of a better explanation, is relieving pressure into the engine (bigger hole for air to escape), but a whistling sound seems like some sort of vacuum leak. I don't know if this was any help, but I hope you find your problem.

 

[DavidT]

Late reply, but I'm not exactly sure how the gasket routes but if that is part of sealing the throttle body, it could definitely be causing a vacuum issue (noise, possible codes). A couple of ways you could check where the leak is, is by using a smoke machine, a very useful tool or using a mechanics stethoscope to listen for the noise. Just looking at the picture, it looks like somebody used RTV silicone to try to seal something? Removing the oil dipstick is for lack of a better explanation, is relieving pressure into the engine (bigger hole for air to escape), but a whistling sound seems like some sort of vacuum leak. I don't know if this was any help, but I hope you find your problem.

Thanks for the reply. It’s been in the shop about a week now. Two different mechanics just seem to not be able to figure it out. Today they are stripping it all the way down to lower manifolds hopefully he finds the problem. I’m just so stumped. I’ve tried everything. Last resort is stripping it down and doing it all over. Going to inquire if he has a smoke machine. He saying the upper manifold is getting water but when I opened it to this picture I posted above wasnt no water..

 

[imidazol97]

I'm probably off on this, but are there two gaskets on your PCV valve. Many folks leave off one when replacing the upper intake. There's a gasket on the cover that seals and an o-ring that seals around the circumference of the PCV. Without that gasket intake vacuum goes unfettered into the crankcase. It usually causes noises.

Take off the oil cap and place you hand over it with the engine running. Suck your hand against the opening?

https://www.autozone.com/ignition-tune-up-and-routine-maintenance/pcv-valve-kit/p/dorman-pcv-valve-kit-47033/209245_0_0?cmpid=LIA:US:EN:AD:NL:1000000:HRD:8360258851&gclsrc=ds

 

[DavidT]

I'm probably off on this, but are there two gaskets on your PCV valve. Many folks leave off one when replacing the upper intake. There's a gasket on the cover that seals and an o-ring that seals around the circumference of the PCV. Without that gasket intake vacuum goes unfettered into the crankcase. It usually causes noises.

Take off the oil cap and place you hand over it with the engine running. Suck your hand against the opening?

https://www.autozone.com/ignition-tune-up-and-routine-maintenance/pcv-valve-kit/p/dorman-pcv-valve-kit-47033/209245_0_0?cmpid=LIA:US:EN:AD:NL:1000000:HRD:8360258851&gclsrc=ds

Thanks for the reply. You are not off at all a faulty pcv can cause excess pressure in crankcase. I’ve changed that it stopped for a day and next day drove to work CEL came on for high idle and the squealing whistle noise was back. 🙁 it’s in the shop they are stripping it all the way down again I just hope I can figure it out. It was running perfect but due to age I decided to why not change the gaskets which they were not in great shape upon removal. Now I’m here

 

[BuickGirlFromMars]

View attachment 40508

This intake is stock?The heads and the intake of the earliest series 2 3800 are not as good as later ones. If you have original intake, buy a new one. The 2002 or so later intakes I THINK were the improved but it may be 2003 or 2004. aftermarket new ones generally are fine but some people have better luck with some brands than others

 

[DavidT]

This intake is stock?The heads and the intake of the earliest series 2 3800 are not as good as later ones. If you have original intake, buy a new one. The 2002 or so later intakes I THINK were the improved but it may be 2003 or 2004. aftermarket new ones generally are fine but some people have better luck with some brands than others

Thank you so much for the knowledge. Sorry so late on a reply. I’ve been under the hood changing every sensor possible. I did change the intake manifold. So far the whistle noise hasn’t been as loud. But is still there barley noticeable. I still get a P0507 code for high idle, but did improve from 12 1300rpm to about 1000 1050 rpm. I’m going on the right direction I guess. Still can’t put my finger on the actual problem. Maybe a faulty coolant temp sensor? It does seem to stay oddly cool. I’ll keep the post updated on any findings.

 

[BuickGirlFromMars]

stop replacing good sensors with unknown new ones. IF they arent broke DONT break it!