Camatruder

I get an 32 code when crusing at constant speed in 4th or 5th gear.
I did a search here and found that this is most likely because the cat was removed. The EGR-valve is a negative backpressure valve and is controlled by variations in vacuum and exhaust backpressure.
When crusing at constant speed in high gear with the cat removed there is too much flow and too litlle backpressure so the SES-light comes on. It goes away when driving under different conditions.
I don’t mind the SES-light coming on but is it bad for the engine? Haynes says that too litlle EGR can cause detonation or engine overheating but i can’t see why. In contrary, when crusing at 60 or more mph the engine temperature drops a litlle (to about 140 °F).
I really want to leave the cat out because my sound is really cool now.
What do you guys think?

Ransford2987

That's interesting...I hadn't heard that before, but I'm relatively new here. I put new cats on mine and didn't have any issues, even though they were supposed to be higher flow than stock. From what I understand, you should only have an issue with detonation under heavy acceleration, and I've never experienced any issues with overheating without it. I left mine disconnected for about 3 days until I could put in a new one and didn't have any issues. Mine was sticking and causing some hesitation. I'm going to follow this thread and see what more experienced members say. Do you notice any issues with overheating (at lower speeds or in traffic) or any effect with detonation under heavy acceleration?

Maverick H1L

iTrader: (8)

Code 32 in the 2.8 is set when the vacuum switch attached to the EGR solenoid doesn't sense vacuum going out of the solenoid. Check for a good PORTED vacuum input (receives engine vacuum ONLY with throttle plate open) to the solenoid first, because the EGR solenoid assembly isn't anywhere near as cheap as it used to be and shipping to Belgium is going to STINK. It's also only set while cruising, so you won't see it in stop-and-go traffic.

The EGR valve is not a negative backpressure valve on the V6. Otherwise I would have had a lot of issues with a gutted cat (never got 32 again after replacing the EGR solenoid assembly).

EGR puts a little bit of exhaust back into the intake, where the cylinders draw the gases back into the cylinders. This reduces combustion temps to keep NOx (oxides of nitrogen) emissions down along with coolant temps and possibility of knock/detonation. The coolant temps don't go up much with malfunctioning EGR unless you have other cooling issues, and you obviously don't.

Camatruder

So the EGR system in a 2.8L only activates while cruising at constant speed, meaning i'm having trouble with my vacuum all the time??

I measured the vacuum and it's only 15" Hg at idle and 21" Hg at 2000 rpm. It should be about 21 at idle, right?? Also here in Belgium ?? I'm living aprr. 20 ft above sea level.

I checked all the vaccuum lines, tested all conections with start pilot, recently i renewed the intake manifold gasket (because i had white smoke) and did a compression test which was ok (meaning the head gasket is ok).

On the other hand shouldn't 15" be enough for the EGR to work properly? My old Chiltons says 5" is enough.
With the engine a normal temperature and rpm steady at 2500 i feel with my finger that the egr-valve opens.
So maybe the EGR-solenoid assembly is defective. Can I test it somehow?

Any idea's on how to proceed ?

Maverick H1L

iTrader: (8)

You're measuring the MANIFOLD vacuum (full time source)... You need to check the PORTED vacuum (only activated with throttle open) source to the EGR solenoid. You should be measuring manifold vacuum at the lower port of the solenoid (AT the solenoid connection) with the throttle plate opened (NOT when closed). And also check to make sure that you measure the same at the switch if the EGR is triggered. If there is no vacuum to the switch, but there is to the valve, code 32 will set. If the switch is bad, code 32 will set. If the car is in Park or Neutral and the valve opens with the throttle opened, there could either be a wiring problem or the solenoid is bad.

Turn the ignition on without starting the engine. If you can get a vacuum pump, hook it up to the tube that runs to the throttle body from the solenoid. If the valve opens with the vacuum pump, remove the vacuum and disconnect the wiring from the solenoid. Apply the vacuum again, and if the valve continues to move, then the solenoid is bad.

XxXChrisGXxX

iTrader: (1)

I use to have this problem, it turned out to be the little nipple on the EGR was "used" sort of speak. I bought some small tubing and used it to seal all of the nipple connections.

If that make sense.

Camatruder

Got a hold of a vacuum pump. My solenoid does not hold vacuum very well under any circumstance. Ignition on or off, electrical connector installed or disconnected, diagnostic terminal grounded or not, it always looses vacuum at the same speed. I'm 100 % sure my connections were tight.
So that new stinky solenoid will have to be shipped anyway.
Thanks Maverick H1L and others for the replies.

Camatruder

Man, those things are expensive.
Rockauto and Summit don't have it in stock.
New on ebay : 132 USD.

There's a 2nd hand one on ebay for 25 bucks.
http://www.ebay.com/itm/85-89-Camaro-Firebird-2-8-V6-EGR-Vacuum-Solenoid-with-Coil-and-Bracket-/281093743234?pt=Motors_Car_Truck_Parts_Accessories&hash=item41727e2282&vxp=mtrWhat are my odds this one is still ok ?
With shipping and local taxes and all it will set me back about 60 or 70 bucks.

For the time being can i continue to drive like this or should i plug the vacuum line going to the solenoid?

Ransford2987

You should plug that vacuum line (do you not notice any vacuum or idle issues?). Actually, is it the vacuum line going TO the solenoid, or from the solenoid to the egr? Did you remove the solenoid? If it's the vacuum line going TO the solenoid, plug that one. I dont' think you have to worry about the other. Also, I would buy a new one, just to prevent every having to worry about this issue again. You get what you pay for and you pay for what you get...

Camatruder

Just to confirm. Bought a new solenoid on ebay and no more SES-lights.
Thanks.

Fordvette

Had the same problem, my problem is I couldn't find a replacement, other than Ebay. for now I have the other version of the vaccum solenoid, the all in one version. It looks a little out of place, but not too bad for a quick fix till I find a better one

I forget which car I pulled it off, it was in my box of sensors, that I keep when I do teardowns.