By December 18, 20061 Comments Read More →

1991 Buick Regal Vacuum and Emission Hose Leak

Reader Question Hi!

The ‘honest’ mechanic got my attention because right now, I need an answer to a question pretty quick and essentially it is a yes/no type of answer.

Technical particulars:

I have a 1991 3.1 Buick Regal VIN T MPFI vehicle with a emission hose routing configuration of LBP. It appears GM in their wisdom made at least 15 different vacuum hose routing configuration from 1990 – 1994 for the Regal (also includes Chevy’s Lumina). Anyway, here is the question. To change out the ‘vacuum harness’ (that’s what the mechanic call it, I haven’t found a vacuum harness part) you have to remove the upper intake manifold.

Is this true? Is this what GM recommends? I have the vacuum diagram and it looks like to me you don’t have remove the upper intake manifold to install new hoses. Another part that was found bad was the vacuum connection part that plugs into the throttle body. Two of the three hose ports had long longitudinal cracks on the underside of the port.

The reason I’m asking is because the mechanic took the upper intake manifold off and snapped off two of the bolts. He wants me to pay extra for drilling them out and installing helicoils. My position is he didn’t need to take the upper intake manifold off to replace the vacuum hoses.

So, we are in a dispute and it looks like I’ll have to do the repair – I towed the vehicle home. The only hose that looks a little tricky to get to is the one going to the map sensor, but it seems to be accessible to me without removing the upper intake manifold.

So, what do you think?

Thanks for your time!

Hey there

That’s a tough question…and I am not certain about how those vacuum hoses are sold or how to properly remove them…if the manifold does indeed have to come off…I don’t know, but I REALLY don’t think you have to remove the intake to gain access though. I CAN comment on the broken bolts though.

Stuff happens, especially on an older vehicle like yours, and especially on intake and exhaust manifold bolts….they just break. When we break them off in my shop…..we charge the customer a minimal fee, plus the helicoil price to repair it. Its just one of those things that can happen and the older the vehicle……the more chance of it happening.


Austin Davis

1 Comment on "1991 Buick Regal Vacuum and Emission Hose Leak"

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  1. hwertz says:

    I had both a 1988 Buick Century with 2.8L (the 3.1L is a stroked 2.8L) and a 1994 Chevy Corsica with 3.1L. I can see this post’s like 4 years old but what the hey. The vacuum lines on both were in nice shape, but indeed most of the vacuum went over this row of rigid plastic vacuum things that did run under the intanke manifold. There were VERY brittle, and I damaged several on my cars, along with tees which also seemed exceptionally brittle on them. (My 2000 Regal has rigid lines too, even one running into a wiring harness(!) but so far I haven’t busted a line on it yet.. I don’t know if they reformulated the plastic so it’s not so brittle or if the underhood is just less hot and greasy.. whichever 8-). )

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