Where is the PCV valve located?

JJSMONTE

MEMBER
1995 CHEVROLET MONTE CARLO
3.4L
V6
2WD
AUTOMATIC
180,000 MILES

A few days ago, my 95 3.4l DOHC blew off a small vacuum line along with the large hose that goes from the brake booster to the intake. Lost brakes and idle control due to the large line being disconnected. Reconnected both lines and runs fine, but the large brake booster hose collapses on itself due to too much vacuum. Suspect PCV valve but not sure and cannot find it to try and replace. I have the new valve already.

Saturday, July 26th, 2025 AT 6:12 AM

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

I don't think the PCV valve will fix the vacuum line you may need to replace it, but here is the location of the PCV valve as requested. Did the engine backfire and that is why the vacuum lines came off? Check out the images (below). Please let us know what happens.

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Sunday, July 27th, 2025 AT 11:30 AM

JJSMONTE

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3 POSTS

The engine must have backfired. It was right as I started the engine.

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Monday, July 28th, 2025 AT 7:25 AM

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

Yep, that will do it, did you find the PCV valve?

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Monday, July 28th, 2025 AT 12:39 PM

JJSMONTE

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3 POSTS

No, I haven't found it. Kind of hard to tell what I'm looking at in the diagram, and I was expecting it to be on the valve cover. What should I look for that could have caused it to backfire?

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Tuesday, July 29th, 2025 AT 3:22 AM

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

It looks like the PCV might be under the intake manifold. A back fire can be caused by the engine not cranking over enough before running which will make it "cough" or you need to replace the spark plugs, wires and coil assembly.

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Tuesday, July 29th, 2025 AT 10:43 AM