[texas1al]

'84 258. Pretty sure I've got a major vacuum leak. The idle mixture screws on BBD are out 4-5 turns. All the vacuum hoses are fine, so I'm guessing it's the intake manifold gasket (or maybe the EGR???)

A few questions - 1) Do I have to remove both the intake and exhaust manifolds to replace the intake gasket? I've heard the exhaust bolts can be a PITA. 2) I've read posts about using Permatex sealer - is this the same as RTV or am I missing something.

Any tips would be appreciated. How long does a job like this take?

Thanks
Al

 

[LEVE]

1. Take off BOTH manifolds,
2. Replace the gaskets as a set...
3. Be prepared to have the exhaust manifold face machined,
4. And the runners aligned.
5. It took me a good day by the time I was done...
6. I did use Permatex HiTemp Orange on BOTH sides of each gasket,
7. It will help seal,
8. And save a "do-over" project.
9. Be sure to re-torque correctly, and
10. Using the recommended torque pattern.
11. And yes, bolt/nut removal is a PITA...
12. Soak the bolts/nuts in your favorite penetrate,
13. For at least 24 hours before removal,
14. You'll thank yourself for it,
15. Or you'll be getting to know you're machinist,
16. Up close and personal.

 

[texas1al]

Thanks Leve, is gasker sealer the same as RTV.

 

[LEVE]

In reply to:

is gasker sealer the same as RTV.

[/ QUOTE ] 1. Humm... good question,
2. Yes, and No...
3. I'm looking at the product now...
4. The lable says "High Temp RTV Silicone Gasket Maker"...
5. But somehow I think it's a little different from plain ol' RTV.

 

[lindy80cj7]

RTV is a gasket sealer but not all gasket sealer is RTV.

 

[2157]

Al,
Before you get all carried away with a major process like that, check the O2 sensor. I had the same problem after the ignition upgrade. When i replaced the O2 sensor, the problem went away. just my $.02 to save a major project.

 

[texas1al]

Thanks Rich, O2's brand new so I think it's going to require a new intake gasket.

 

[lindy80cj7]

Did you put a vac gage on it? That will tell alot.

 

[texas1al]

No, I don't have a vac-gauge so I don't know what it's pulling. I'll try the propane bottle trick near the gasket tonight, but I'm pretty sure that's it. I re-plumbed the entire engine and no leaks anywhere else.

 

[lindy80cj7]

There not expensive and really gives you alot of useful info. WD-40 can also be used to locate a vac leak.