3.5 problem....this is some crazy stuff

[teejay3800]

My dad took the Aurora to the dealer and from what he told me, the 3.5 has a weird system that uses heat from exhaust gas, and routes that heat back into the coolant system somehow. This is to increase the coolant temp faster after a cold start to get heat to the cabin quicker. Well aparently there is a leak in a gasket involving a cross-over pipe of some sort related to this system.

Can anyone give me any info on this strange exhaust/coolant system? Anything at all anyone can give is appreciated.

[Custom88]

heh. not exactly. I think he's referring to the AIR system. Basically it has an air pump that pumps air back into the heads to heat up the catalytic converter faster. I don't know exactly how it works but I do know that it doesn't do anything with the coolant.

[teejay3800]

custom88 said:

heh. not exactly. I think he's referring to the AIR system. Basically it has an air pump that pumps air back into the heads to heat up the catalytic converter faster. I don't know exactly how it works but I do know that it doesn't do anything with the coolant.

It definitely has to do with coolant, because a coolant leak is what alerted us to the problem. I know this sytem sounds crazy, but its exactly how the Olds dealer described the problem to us. Whatever it is, it's very labor-intensive to repair.

[Custom88]

well, the AIR system has a tube that goes directly into the head of the engine.. if a gasket is bad then coolant can leak, yes. That doesn't mean that the exhaust gas is being introduced to the coolant. If that were true the coolant would be black and solid sludge over the course of a few hundred miles. If the dealer actually does think that the exhaust gas is routed to the coolant I'd suggest taking your Aurora to another dealer.. seriously. How does your oil look? Is it milky at all? Sounds like a headgasket to me, personally..


This is a photograph of where the pipe for the air system enters the engine. This is part of the emissions system that qualified the Aurora to be considered a "low emissions" vehicle. Its purpose isn't to heat up the engine faster however, it is meant to heat up the catalytic converter more quickly to reduce emissions. as you can see this is right near the head. a faulty head gasket would allow the engine to leak coolant in this area. it isn't a fault of the air system though specifically.

[teejay3800]

Thank you for the reply and comprehensive explanation! I notice you live in Battle Creek; I myself am from Portage. I will give my dad the link to this thread and see what he thinks. Personally, I thought the idea of routing the exhaust gas itself into the coolant was total BS. What you described sounds like what is most likely the problem. I agree that if the dealer thinks the exhaust is supposed to enter the coolant, we should switch dealers. However, the dealer the car is now in was an Olds dealer for many years and is very reputable. I'm sure there were some communication problems between the dealer and my dad, and from my dad to me. Thanks again for the info!

[kobrak]

Actually, aren't they talking about the heating system in relation to getting the heater to blow hot air quicker? Isn't this fairly common on todays cars?

[Custom88]

teejay3800 said:

Thank you for the reply and comprehensive explanation! I notice you live in Battle Creek; I myself am from Portage. I will give my dad the link to this thread and see what he thinks. Personally, I thought the idea of routing the exhaust gas itself into the coolant was total BS. What you described sounds like what is most likely the problem. I agree that if the dealer thinks the exhaust is supposed to enter the coolant, we should switch dealers. However, the dealer the car is now in was an Olds dealer for many years and is very reputable. I'm sure there were some communication problems between the dealer and my dad, and from my dad to me. Thanks again for the info!

let us know what the dealer thinks it is then we can go from there. My brother actually lives in Kalamazoo and goes to Western. My brother actually has a apartment in K'zoo though, and I go to KCC in B.C.!

[Aurora40]

kobrak said:

Actually, aren't they talking about the heating system in relation to getting the heater to blow hot air quicker? Isn't this fairly common on todays cars?

I've never heard of a car using exhaust gas to heat the heater core faster. For one, the heater core has coolant running through it, so it won't get any hotter than the coolant is. For two, using exhaust gas in the ventilation system is really a risky idea unless you are using a very clean-burning fuel.

[teejay3800]

custom88 said:

let us know what the dealer thinks it is then we can go from there. My brother actually lives in Kalamazoo and goes to Western. My brother actually has a apartment in K'zoo though, and I go to KCC in B.C.!

I go to WMU as well and have an apartment near campus. The car is supposed to be done by the end of the day, so hopefully by tomorrow I can give you the full scoupe on it.

[dk58]

If anyones sees this reply... Is This the secondary air pump? could this run a 14xx code that has been discused on other posts? Would this make an incredible whinng noise?

[Custom88]

the air pump can make a loud whining noise, yes. Mine does make a whine but it's pretty quiet. I can definatley tell when it's on though. It just makes my engine sound like it's idling really high.