: EGR Valve Questions



DopeStar 156
06-29-06, 02:09 PM
I had my car checked out and my EGR valve is shot. They hooked up vacuum to it and the car didn't stall like it was supposed to, indicating that the EGR valve is shot. I'll replace it myself since it looks simple enough to do by both looking at it and the FSM's instructions. I called around and got some prices on EGR valves and I'm a little confused at these fluxuations in price....

Cadillac: $112/order
Auto Zone: $90/in stock
Advance Auto: $50/order

carnut
06-29-06, 02:27 PM
If an EGR is faulty, usually it wont hold vacuum. If activating it with a hand held vacuum pump and the engine speed is unaffected, I would suspect the exhaust passage to it is plugged up. The difference in pricing has to do with proper application. The Cad. part is specific to your car , the aftermarket ones are generic, meaning they are designed to fit many engine configurations and in some cases will cause driveabilty issues because the metering of exhaust flow is not precise. If in fact, the EGR is faulty, replace with the GM part number.

DopeStar 156
06-29-06, 03:51 PM
If an EGR is faulty, usually it wont hold vacuum. If activating it with a hand held vacuum pump and the engine speed is unaffected, I would suspect the exhaust passage to it is plugged up. The difference in pricing has to do with proper application. The Cad. part is specific to your car , the aftermarket ones are generic, meaning they are designed to fit many engine configurations and in some cases will cause driveabilty issues because the metering of exhaust flow is not precise. If in fact, the EGR is faulty, replace with the GM part number.
So you think I should get the $90 one?

90Brougham350
06-29-06, 04:19 PM
Glad you've nailed the problem. The higher-price units are most likely the better units, GM parts. You want these. You're correct in assuming it's a very easy job to replace. While you're at it, replace the factory plastic vacuum tubing with some good new rubber line from the parts store. You'll be amazed at how much better the vehicle does with the correct new EGR valve. Good luck!

N0DIH
06-29-06, 05:07 PM
Did you read my post on HOW to test that EGR? It isn't that simple to test! You are likely replacing a good valve.

It IS simple, but the functional test for the EGR on these cars DOES NOT ever require putting vacuum directly on the valve.

caddydream
06-29-06, 11:12 PM
I paid $30 for the EGR valve on my Olds Custom Cruiser with the 307. Bought it at Advance Auto and having good luck with it so far.

I noticed it is made better than OEM. Does not have the cheap plastic top but is metal.

After many years the rubber diaphram degrades and leaks.

From what I have seen a 307 is the same in a Caddy, Buick or an Olds.

N0DIH
06-29-06, 11:55 PM
I've never seen a plastic top EGR on a 307. All the ones I have seen are a moderate gauge steel valve.

I have one off my 307 in pieces downstairs. I tore it apart just out of curiousity. I'm sick that way I know.... Who else would take an EGR valve apart just to see how it ticks?

DopeStar 156
06-30-06, 12:56 AM
The guy at the shop I visited applied vacuum to the thing and the car didn't stall. He told me the EGR valve wasn't functioning at all. When I take it off I'll clean out the two holes under it, then replace the valve.

carnut
06-30-06, 04:58 PM
I guess if you're bound and determined to replace a part prior to proper diagnosis then putting it on the forum kind of wastes other peoples time! You can lead a horse to water, but...........

DopeStar 156
06-30-06, 11:21 PM
I'm not being stubborn, I'm just reiterating what was told to me. Eitherway if the valve is good or bad, I'm sure it needs to be removed and cleaned out at least. I was just thinking after being 17 years old the EGR Valve is probably in a condition where it would need replacing.

DopeStar 156
06-30-06, 11:28 PM
I got this from turbojimmy in the "Dammit, Dammit, Dammit!!!" thread.


Yeah that's it. Doesn't look like you have to take the carb off. Just that one bolt. If you have access to a vacuum pump (like a Mity Vac) you can put vacuum on it and make sure it's opening and closing like it should. It could just be clogged, though.

Make sure you get a new gasket, too. If it's never been off you may destroy the gasket while removing the valve. The auto parts store should have one.

Jim

This is exactly the test that was done and I was told it wasn't functioning and was most likely clogged. That's why I'm gonna at least clean it out and probably end up replacing it if it's that shot. The mechanic I took it to staid there were two holes under it, intake and exhaust. one should be clogged, I forget which he said it was. He suggested I stab at the clog with an ice pick or something similar to clean it out.

brougham
07-01-06, 12:21 AM
Usually if it's clogged it's inside the intake manifold or by the heads and you have to take the whole intake manifold off to fix it.

N0DIH
07-01-06, 09:37 PM
Read how I said to test it. What type of EGR valve did I mention it was? It cannot be tested that way, it will ALWAYS fail, even a new one will "fail".

Only a ported or a negative backpressure EGR can be tested with a vacuum pump. The one in your 307 cannot be tested that way. Period.


I got this from turbojimmy in the "Dammit, Dammit, Dammit!!!" thread.



This is exactly the test that was done and I was told it wasn't functioning and was most likely clogged. That's why I'm gonna at least clean it out and probably end up replacing it if it's that shot. The mechanic I took it to staid there were two holes under it, intake and exhaust. one should be clogged, I forget which he said it was. He suggested I stab at the clog with an ice pick or something similar to clean it out.

brougham_geezer
07-05-06, 12:56 AM
EGR on the hearse was long done, and causing major brake, and idle problems. We didn't replace it, we closed it up. Our guy knows what he's doing and did a great job of it. The car runs fantastic now. Is this an option where you are Dope?

N0DIH
07-05-06, 11:06 AM
The fuel mixture will be way off if you just block it off. You can't simply do that, it actually makes emissions worse, which is why I am not a fan of EGR the way it is implemented. It doesn't allow for the part to be bad and actually makes emissions WORSE than if it was actually designed out (software turned off).

Simply put, it must be there unless you can get into the PROM and turn EGR off properly, else it will EXPECT it to be there and lean out fuel and increase timing. And we can see what it does to emissions.

DopeStar 156
07-09-06, 12:50 AM
I'm back and ready to tackle this tomorrow. I'm gonna take the valve off and clean it out then put it back on and see what happens.....

stoutman26
08-22-11, 10:55 PM
I have a '95 Cadillac Fleetwood Brougham that needs its EGR valve replaced. Does someone have a detailed schematic or know of a place to get one? I can see that it is on the back of the engine. Does anyone know what size socket you use? It looks like a star but I could be wrong. Are there just two bolts? It sounds stupid but how do you work on it since its just far enough out of reach. Do you recommend just leaning on the side panel or is there an easier way?

jayoldschool
08-23-11, 10:44 AM
It's only two nuts. 10mm, if I recall. Use box wrench, the ratcheting kind if you have it. Replace the gasket, too. I can reach no problem, but I'm 6'7". You can stand on a box if you need to...

outsider
08-23-11, 12:47 PM
lol no wonder you got into the Cadillacs Jay! they're the only cars with enough leg room to accommodate you! lol

stoutman26
08-24-11, 09:17 AM
Jay

Picked up a BWD - EGR Valve Part # EGR1098. I took off the old one with a 1/2" box wrench which worked great...! Thanks for your help. Now when I turn on the car the engine starts to act like it wants to stale but only when I put it in drive and my foot is on the break. Do you think I didn't tighten the nuts enough or do you think that it is the wrong EGR valve replacement? Or something else?

Matt

outsider
08-24-11, 09:20 AM
definitely sounds like an EGR problem...did you connect everything back to the new EGR valve correctly?

Also did you replace the gasket? You may want to try cranking down on the bolts a little more just to be sure it's snug.