Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's, Olds 98 91-96, Buick Lesabres and Park Avenue 91-96. Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.
Hello,
there is some plastic cover behind the engine that probably was heated by the engine all the years.
I touched this cover by mistake and it just cracked easily, when I touched it again I felt that the plastic was very dry and every additional contat was cracking it more, even slight touch.
I saw that there was some kind of sponge under, but don't what it realy used for. does anyone now?
There's just insulation behind it. Not critical, but does keep heat and sound out a bit.
WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers 2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights
That is a plastic cover with insulation underneath that runs over the airbox for the HVAC. It is usually not a concern, and many are affected by this condition as time goes on, myself included.
~Randall~
1993 Buick Park Avenue - 197k - Some odds and ends done - Simply won't die
1994 Buick Regal - 78k - Bone stock - Always ready for a good kicking
1990 Oldsmobile 88 - Gone to a better place
I got a roll of aluminum foil heat shield tape and covered over the plastic from top to as far as I could reach below. All underneath the blower motor casing as well. You may see some remnants of the factory heat shield tape (it usually mostly falls off) to us4e as a guide.
Your blower motor cover has probably disintegrated and there is now an opening in the firewall right above the exhaust pipe. Behind the blower motor cover is the vent air inlet duct work. So, yes you can be drawing in heat from the engine compartment directly into the vent system.
We can't see the blower motor cover in this picture. However its very common for the cover to crack and disintegrate where the rubber cooling hose attaches to the cover. An open hole in the blower motor cover is just as I described in my post above. Given the condition of what we can see in the photo, its also likely the blower motor cover is cracked.
You can see the edge of the cover on the right hand side of your picture.
While the cover may crack, it won't cause a path for hot engine air to get into the HVAC. The metal of the blower housing itself would have to fail first.
WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers 2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights
"While the cover may crack, it won't cause a path for hot engine air to get into the HVAC"
I just replaced my blower motor that had a cracked cover. The rubber motor cooling hose was dangling and unconnected to the disintegrated cover. That cooling hose is connected on one side to the firewall leading directly to the vent duct system. The blower motor itself has a hole on the back of the motor that allows air to circulate into the motor via the other side of the cooling hose. Hot air can and will get into the HVAC if this hose is not connected on both ends. The interior of my car is much quieter now that the cooling hose is securely connected at both ends.
EDIT:
I think one really needs to replace a blower motor for themselves and inspect how that rubber cooling hose is connected to the HVAC and back of the blower motor case to fully understand what I'm trying to explain. Its a poorly engineered design for sure.
Last edited by reb on Thu Aug 09, 2012 12:21 pm, edited 1 time in total.
I have replaced the motor. If the hole at the bottom of the cooling hose is, if anything, pressurized slightly when the blower is on, so it would be blowing into the engine bay, right? The top end just goes into the chamber with the electricals of the motor, sealed from the HVAC. Is that different on later 90's?
WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers 2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights
The cooling hole on the back of the metal blower motor is not sealed on my '97. It vents right thru to the oppossing fan blades into the HVAC ducts. Its a closed system only if the cover is not cracked and coolant hose is sealed on tightly.
But if the blower cover gets cracked and or the little rubber hose falls off the cover. When the fan is on it will pull hot engine compartment air right into the HVAC from the opening where the hose was connected to the cover or thru a crack in the cover.
J Wikoff, in regards to the rubber cooling hose, it is pressurized and thinking this thru again . If it gets disconnected from the blower cover air will now blow thru the hose into the engine compartment but only when the fan is on- you are correct. But when the fan is off, there now exists an opening for noise and possibly heat to enter the HVAC ducts thru the hose . Again, if the fan is on and the hose is disconnected from the cover, heat will be drawn in directly thru the fan. None of this is an issue if your cooling hose is properly connected and the cover is not cracked.
95naSTA,
The blower motor cover on my car is round and plastic with a larger hole than the metal one you show. What car is the one you show for?
So in conclusion, this brings us to how and why the cooling hose gets disconnected. Firstly its connected to the plastic blower motor cover at a location closest to the exhaust on the underside. Over time the plastic blower cover disintegrates from the constant exposure to high heat and the hose no longer has a connection point. Making matters worse is the aluminum heat shield tape usually peels away from that area no longer defected the heat.
Last edited by reb on Thu Aug 09, 2012 4:15 pm, edited 1 time in total.
Here you can see pictures of the blower motor. Not sealed but indeed vented on both the motor and impeller side. The large round hole is where air from the cooling hose enters thru the blower cover.
Hi guys, I'm thinking im gonna replace my blower motor on my 98 pontiac bonneville sse because it make a grinding noise when on it will come and go the noise so I believe its worn out. I didnt remove it and cleaned it up but the plastic cover on the back of the motor has broken to pieces I was only able to Savage enough of it to go over its mounting bolts I don't know what the cover looks like as it was never fully there when I bought the car and my heat shielding is also peeling off and there is that circular hole to the bottom left of the blower motor and I didn't notice any hoses or any covers for it while I was taking out the old fan to inspect it and clean out the vents I have noticed though during startup there is more airflow coming through to the windshield vents and it will steam up the window here and there. So my question do you guys is do you know a reputable blower motor replacement I can purchase that comes with the cover and what would the name be for the hose that may or may not go into that other whole thats open? Any additional information on at least the open hole and what it needs would be grate. Thanks
Also it probably would be helpful if I was able to view the photos you guys share but it's an old post and they no longer are available to view.
The plastic cover is just that, It covers an actual metal box. I opted to just completely remove all of the plastic and have the box ceramic coated. You could do the same and just rattle can it. The motor will still attach to the metal box without issue. I don't have a good rec for the motor. Just try and find something with reviews.
95 SLE... a keeper. 241k miles. Low and Slow.
97 BMW 528i
98 Infiniti vq35'd i30: 13.3@104mph, 30MPG Hwy (RIP)
02 Jag X-type
03 BMW M5
05 Chevy Cobalt LS
07 Infiniti G35s 6MT (Sold)
07 Ducati Monster S2R 800 with DS1000 swap
83 Yamaha IT175K
72 Yamaha DS7: '74 RD250 swap, JL chambers
