# Is there a difference between Combi Valve and EGR Valve?



## StephenK (Oct 3, 2001)

The dealership just told me that my combi valve's brass freeze plug is leaking exhaust fumes. Now, just 7 mos. ago, I replaced the EGR valve, which at the time they were calling the "Combination valve". Are they the same thing? The dealership said no, but I don't exactly trust them. And if they are, then I get my combi valve replaced under the 1 yr. parts warranty free!
Thanks,
Steve


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## StephenK (Oct 3, 2001)

Anyone?


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## smd3 (Aug 5, 2001)

*Re: Is there a difference between Combi Valve and EGR Valve? (StephenK)*

When I had a dealer look up a DV in their ETKA system it was listed as a Kombi valve. I think it's a pretty broad term.


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## gwebel (Feb 13, 2001)

*Re: Is there a difference between Combi Valve and EGR Valve? (smd3)*

The Kombi valve is the valve that lets the secondary air pump admit air into the exhaust stream at startup and sometimes idle to heat up the catalytic converter. This is so the cat will work at its maximum efficiency. The EGR (exhaust gas recirculation) valve recirculates unburnt exhaust fumes back into the combustion chambers (cylinders) to increase the quality of emissions. As far as the diverter valve is concerned, in ETKA, it is refered to as a "change over valve"; so all of these are different valves.


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## StephenK (Oct 3, 2001)

*Re: Is there a difference between Combi Valve and EGR Valve? (gwebel)*

Cool, thanks for the explanation!


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## chris86vw (Feb 23, 2000)

*Re: Is there a difference between Combi Valve and EGR Valve? (gwebel)*


_Quote, originally posted by *gwebel* »_The Kombi valve is the valve that lets the secondary air pump admit air into the exhaust stream at startup and sometimes idle to heat up the catalytic converter. This is so the cat will work at its maximum efficiency. The EGR (exhaust gas recirculation) valve recirculates unburnt exhaust fumes back into the combustion chambers (cylinders) to increase the quality of emissions. 

Its the same valve, your talking about the same process just at two different ends of what is doing on.


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## rawlmark (Nov 19, 2001)

*Re: Is there a difference between Combi Valve and EGR Valve? (chris86vw)*


_Quote, originally posted by *chris86vw* »_
Its the same valve, your talking about the same process just at two different ends of what is doing on.

True, but they could still be refering to 2 different valves, right? How many Combi Valves are on the 1.8T? What is exactly a Combi Valve? I would think any valve allowing air to go in more than one direction could be considered a Combi Valve ie: Diverter Valve, EGR Valve, maybe even an N75 Valve.
Anyone really know?


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## chris86vw (Feb 23, 2000)

*Re: Is there a difference between Combi Valve and EGR Valve? (rawlmark)*


_Quote, originally posted by *rawlmark* »_
True, but they could still be refering to 2 different valves, right? How many Combi Valves are on the 1.8T? What is exactly a Combi Valve? I would think any valve allowing air to go in more than one direction could be considered a Combi Valve ie: Diverter Valve, EGR Valve, maybe even an N75 Valve.


True it could be that sort of confusion, however he states:
"The dealership just told me that my combi valve's brass freeze plug is leaking exhaust fumes. "
I would check the part number on the part you already had replaced against the one they are saying you need now. Chances are they are referring to the same thing, especially the way I am reading their description of whats wrong.


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## gwebel (Feb 13, 2001)

*Re: Is there a difference between Combi Valve and EGR Valve? (chris86vw)*

No, the EGR and the Kombi valve are two different parts, two different systems. The EGR is located next to and underneath the coolant resivoir (Golf/Jetta), or next to the airbox (Passat), and the Kombi valve is located on the back of the head (next to cylinder 4) on either car. The EGR has a line in from the charcoal canister, and out to the throttle body. The Kombi valve has a line in from the secondary air pump, and is connected to the exhaust manifold, and also has a vacuum line attached to the side controlling the actuation from the solenoid that controls it. So, the dealership is telling him that the Kombi valve is stuck open, letting exhaust escape through the secondary air system. They are not connected, but both systems deal with emissions... one on the exhaust side and the other on the intake side.


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## chris86vw (Feb 23, 2000)

*Re: Is there a difference between Combi Valve and EGR Valve? (gwebel)*


_Quote, originally posted by *gwebel* »_No, the EGR and the Kombi valve are two different parts, two different systems. The EGR is located next to and underneath the coolant resivoir (Golf/Jetta), or next to the airbox (Passat), and the Kombi valve is located on the back of the head (next to cylinder 4) on either car. The EGR has a line in from the charcoal canister, and out to the throttle body. The Kombi valve has a line in from the secondary air pump, and is connected to the exhaust manifold, and also has a vacuum line attached to the side controlling the actuation from the solenoid that controls it. So, the dealership is telling him that the Kombi valve is stuck open, letting exhaust escape through the secondary air system. They are not connected, but both systems deal with emissions... one on the exhaust side and the other on the intake side.

Thats the evap purge valve not an EGR. Think about where you are saying they are located and what the function would be.
Fact of the matter is there is no EGR valve on these cars only secondary air, the Kombi valve does get referred to as an EGR at times though.


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## gwebel (Feb 13, 2001)

*Re: Is there a difference between Combi Valve and EGR Valve? (chris86vw)*

Chris-
You are totally right... I feel like a jack ass. I am getting my MK 3 and MK 4 cars mixed up. I guess being a tech gets to you after a while. I am going to have to look at VESIS at work tomorrow to get myself straight. On the other hand, if you are right, StephenK has been misinformed if the dealership. I am anxious to post tomorrow on my findings from VESIS.


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## chris86vw (Feb 23, 2000)

*Re: Is there a difference between Combi Valve and EGR Valve? (gwebel)*


_Quote, originally posted by *gwebel* »_Chris-
You are totally right... I feel like a jack ass. I am getting my MK 3 and MK 4 cars mixed up. I guess being a tech gets to you after a while. I am going to have to look at VESIS at work tomorrow to get myself straight. On the other hand, if you are right, StephenK has been misinformed if the dealership. I am anxious to post tomorrow on my findings from VESIS.


I was checking while I was posting last nite. No MK4s have EGR, well not in the US at least not sure about other countries. b5 passats also dont' have it, since that is what we are talking about anyway.


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## JettaRed (Aug 14, 2000)

*Re: Is there a difference between Combi Valve and EGR Valve? (gwebel)*

gwebel,
Actually, you were right in your description of the Kombi valve. It is simply used to allow the secondary air pump inject filtered air (the 1" tube coming out of the top of the airbox) into the exhaust stream (creating a false lean condition) to heat the cat faster to optimal operating temperatures. It does nothing to recirculate unburnt fuel; it's not even connected. Cars without an air pump will not have a Kombi valve.
(Revelation: Sometimes the dealer service personnel don't know what they're talking about.)


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## RabbitGTIdriver (Jun 14, 2003)

New vws do not use EGRs


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