: intake gaskets



stoveguyy
08-05-08, 01:27 PM
i had my intake off last year to do the headgaskets. i reused the old intake gaskets though they were fairly flat. i had a miss since the repair so i decided to change out the intake gaskets this weekend. not too hard. take off intake, clean surfaces, put on new ones, torque evenly. so today i get code 171 and 174. lean, both banks. what would i gain by removing intake to look at the gaskets and reinstall? i was very careful putting them on. maybe the bolts are slightly loose? any tricks to replacing gaskets i am not aware of?

Submariner409
08-05-08, 04:02 PM
Fortunately, the new gaskets are reusable. Post your car, year, and mileage by your login name ^^^ like mine. Use the USER CP at the top left of the page. Makes diagnosis easier.......as in Kenworth or Honda ??? :sneaky:

While you're back in the intake area, check the connection between the manifold and throttlebody: even a small leak there will set codes. Check the PCV pipe from the rear cam cover to the front end of the intake manifold. Check the overpressure valve for leaks. Use a stethoscope, as modified in these threads for quite a while, to snoop for a vacuum leak around each intake runner and fuel injector (injector bases are sealed by O-rings....)

The manifold torque is only 9 ft/lb. Not squeak tight by any means.

tateos
08-06-08, 05:05 PM
Good one Sub:

Check the overpressure valve for leaks.

It is the flap on the intake manifold on the front of the engine - the opposite end from the throttle body. It has been known to leak sometimes. Maybe you jarred it partially loose when you replaced the manifold gaskets?

stoveguyy
08-07-08, 11:20 AM
i got a in/lb torque wrench and checked the bolts. they were not quite at 9lbs. i did check the blow off valve when i put on the intake. i opened it and checked the spring and i am pretty sure it was seated ok when i put on the intake. i still got the code last night when i went for a drive. i checked every line and connection around the intake. i might loosen and retighted all the intake bolts again.

Raze
08-08-08, 11:33 PM
Check all of your vacuum lines to and fro...

stoveguyy
08-09-08, 02:06 PM
ok, i was making my last pass at 9lbs on the bolts and cracked the corner of the intake near the pass firewall. damn. it just did not feel right going down. i checked with some boneyards and our local "superyard" has them used for $160. bobs auto parts has them for $40. of course the super yard says bobs stuff is junk. they reject 1/2 of their parts cuz they are warped. is that a big problem?

Submariner409
08-09-08, 04:27 PM
If you can see the entire crack, mix up a blob of 5-minute epoxy and wipe it into the break. Let it set pretty well and do it again. That will get you running again.

:confused: If the manifold corner didn't feel right while tightening, perhaps the gasket is out of place or there's a chunk of something under the corner. Bummer.

Go to www.car-part.com (http://www.car-part.com) and surf around for a manifold. How much is a new one at a dealer???

jeffrsmith
08-09-08, 07:52 PM
I would have to agree with Sub, a little epoxy may save you a bit of cash. If you have the time you may want to try JB Weld - it is epoxy but I have found that it works much better where you may experience higher temps.

Just my .02

Good luck

stoveguyy
08-09-08, 09:21 PM
maybe crack is not a good description. i would say shatter instead. the bolt made a counterbore in the manifold. it does not look good. i got another manifold from "bobs" and it looks ok. maybe tomorrow i will go at it. at least the code 0171 and 0174 is now only reading 0174. looks like 1/2 of the manifold is sealing at least.

Ranger
08-09-08, 09:41 PM
ok, i was making my last pass at 9lbs on the bolts and cracked the corner of the intake near the pass firewall. damn. it just did not feel right going down. i checked with some boneyards and our local "superyard" has them used for $160. bobs auto parts has them for $40. of course the super yard says bobs stuff is junk. they reject 1/2 of their parts cuz they are warped. is that a big problem?
Sounds like bad mouthing your competitor to me. I wouldn't worry about it.

codewize
08-10-08, 11:27 AM
Isn't it 9 in/lb ? No I guess not. Why am I confused.



The manifold torque is only 9 ft/lb. Not squeak tight by any means.

stoveguyy
08-10-08, 11:54 AM
so the used manifold was marked 95 seville. hmm, OBDII and all that? my car is a 96 STS. it turns out the vacuum line fitting for the FPR is the wrong size. of course they are closed on sunday. i checked their inventory online and they have a 97 eldo intake? damn, why not give me the correct part to begin with. maybe they want to get rid of their oldest stock first? and yes, i noticed the tube fitting size AFTER i took off my manifold. oh, the tube fitting on the side of the intake is not even open. maybe it is plugged with carbon? the pcv line on top of the intake is also the wrong size. maybe GM switched some plumbing around. i am not going to cobble it together. just get the right intake.

Submariner409
08-10-08, 02:45 PM
Alldata lists the 2002 intake manifold torque as 90 in/lb, actually 7.5 ft/lb.

codewize
08-10-08, 08:18 PM
Ahh maybe that's what it was. 90 in/lb


Alldata lists the 2002 intake manifold torque as 90 in/lb, actually 7.5 ft/lb.