kev.e

I just had my intake manifold gasket replaced a few weeks ago and sence then i noticed the water temp is higher than before and that it dont run as good as it used to ,rough idle doesnt start quite as good and had to adjust the idle up to 1000 rpm just so it would stay running when at idle in drive ,the other day i noticed that the front and rear intake manifold gasket seals are like coming out the front is out about 2 and a half inches across and the real seal is barely attached just kind of sagging in the back only attached at the corners,my question is would these seals not being in place like they should would that cause these issues im having ?The mechanic said they adjusted the timing best they could and adjusted the points as best that they could ,Would things go back to normal if i took it to a professional and had them redo it?

classicmuscle442

Need a new mechanic, never use the rubber gaskets on ends of intake, anybody that works on vintage cars know this, ask for refund. Without a good intake to block seal you have vacuum and oil leaks. Do not know what area your in but if you post your location someone on here may be able to help you out.

kev.e

I live in near Tomah Wisconsin not far from the Dells ,so is rough idle harder starts and running hotter some of the symptoms that not having seals on rite would be?

classicmuscle442

Yes, the engine is running lean, need to repair before damaging engine.

RetroRanger

kev.e

Thank,s for your responses,when i told the mechanic about the seals he said it wouldnt effect how the engine ran they were just there to keep dust out and keep it from leaking oil.He said if i want i could bring it back and he would just pull the seals the rest of the way out and seal the gaps up with silicone ,but from what i'm hearing from you guys is that the whole thing needs to be redone ?

joe_padavano

Your mechanic is correct in that the end seals don't affect how the engine runs. The fact that the engine runs poorly suggests that there is an additional problem with the intake installation.

Out of curiosity, why did you have the intake gasket replaced in the first place? They don't typically go bad on Olds motors.

kev.e

it was replaced because when its cold i noticed it was leaking a little antifreeze i noticed it was coming from the back of the intake.there was always some antifreeze on top of the oil filter it would drip down from the intake

joe_padavano

Are you sure it wasn't the heater control valve that screws into the back corner of the intake? That's a far more likely failure.

kev.e

I remember hoping it was that would of been much easier and cheaper fix ,I heard about that somewhere else and i checked it ,it was coming from the intake the mechanic saw where it was coming from to,so what would you recommend i do?i'm stumped at this point ,just want to get it running good again but not sure how,do i take it to a professional and have them redo the intake manifold gaskets ?

Fun71

Was the carburetor removed when the intake manifold gasket was replaced? If so, there could be a vacuum leak there.

kev.e

I think it was they said a bolt was stripped for the carb and had to get a helicoil to get the bolt to stay tight ,can i check it by spraying a little starter fluid around the bottom of the carb and see if the idle goes up or down?maybe i should try that around the intake gaskets to ,at this point i'm not sure why its doing what its doing.

1970greensupreme

The starter fluid trick will work but beware, I've seen a good fire start and blow back in a guys face who had an arcing wire

1970greensupreme

Laugh but if you want to be safe I had a friend who had a vac leak in a newly built and painted SBF. I got a cigar and blew in through a manifold vac port while covering the throttle body and found a leaking plastic T on the firewall. Kinda a red neck smoke machine, LOL. If he used starter fluid or carb clean it would have buggered up his freshly painted manifold etc

kev.e

Good advice,just need to find a cigar lol at this point im willing to try anything just to get it back to normal ,hate when its not running rite.the mechanic put new points in the car same time but said he had an old timer from work come down and help him set the points and dwell cause he new all about older cars ,so i wouldnt think that would be the issue.

kev.e

Big question rite now is should i have the intake manifold gasket redone?The guy who did it said if i bring it back he'll pull the seals the rest of the way out and just silicone it in place.is that even something to think about ,or is it a big no no?PLEASE help need all the advise i can get?Thank,s in advance!

RetroRanger

kev.e

Thank,s for the reply ,so do you agree with everyone else about not using the front and rear seal and to just use silicone or gasket sealer instead?

1970greensupreme

I wonder if he used the original bathtub metal gasket or composite gaskets

kev.e

I'm not sure which 1 he used.

oldcutlass

While a lot of people don't use the seals, mainly on aluminum manifolds, there are millions of stock engines that have used them. If you are going to redo the intake metal gasket, you need a new one as they are 1 time use only.

RetroRanger

kev.e

Thank's for the response! It is an after market manifold i figured i would have to buy a new gasket kit hoping to get more feedback on if it's for sure better not to use the seals and just use silicone on the front and rear of the manifold?

Fun71

They both do the same thing and work well IF DONE CORRECTLY. I've done it both ways and never had any issues with either..

kev.e

Thank's for your response RetroRanger I,ll look tomorrow at the intake and head ,i was gonna post a pic here this morning of the front seal sticking out but im not sure how to post the pic.

kev.e

Thank,s for the input Fun71, good to know!

1970greensupreme

Not all gasket makers are created the same either. Chrysler makes one for there trans pans that works well. Honda-bond sold at Honda and MB. They set up quicker and are super resistant to oil.

oldcutlass

With an aftermarket aluminum manifold, assuming Edelbrock, the directions say do not use the rubber end seals.

kev.e

Wow i never heard that before,very good to know!I went out and looked and i can see he used metal gasket and it is an Edelbrock performer intake !Thank's for the info!

70W-32

You need to change mechanics. He buggered up your car and now he doesnt want to fix it correctly. I take it he is working out of his garage? Did the "old" mechanic use a dwell meter to set the new points?

kev.e

I,m gonna have someone else do the manifold gasket,the guy i took it to is young but is a mechanic but mainly works on newer cars ,he did do it on the side ,and yes i let him use my dwell meter ,he said he had an older guy from work that knows more about the older cars come over and set the timing points and dwell said he also adjusted the holley carb a little to .

kev.e

Can you guys please tell me what the best intake manifold gaskets to use on an olds 350?and also which gasket sealer and silicone to use on the gaskets and to use on the front and back if i dont use the end seals?

kev.e

Ok just got off the phone with my uncle who's worked on cars most of his life especially the older ones he said he would do the intake gasket ,he used to be a mechanic he's retired now ,was hoping you guys that work on oldsmobiles all the time could give me some advise on which gaskets are better and which silicone and sealer to use ?were just gonna do it like edelbrock instructions show to do and use silicone or gasket sealer on the ends ,so any help on this would be greatly appreciated?

RetroRanger

I just used a typical metal turkey tray from fel pro. and the right stuff silicone on the end seals. i have no other data points

kev.e

Thank's for the info Retroranger!Do you know if the right stuff silicone comes in black?And do you use the right stuff on the gaskets to or is there something else you use there?

classicmuscle442

Yes use the same silicone on the intake gasket but just on the water passages. If the car is just used in warmer weather you could block off the exhaust crossovers under the carb, I used 308 stainless to block mine but there are other materials that can be used.

kev.e

Thank's for the info Chris ,So we can use the silicone for the whole job gaskets,water passages and for 1/4 inch beads for the front and rear of the intake?

RetroRanger

yes silicone for water ports and instead of the rubber end seals. The gasket or turkey tray has raised or embossed areas to seal intake tract.

BillK

Kev,
I am just going to add that on the metal gaskets I always use either "high tac" spray or Permatex "Aviation Form a Gasket" around all of the intake ports. Helps to seal up any irregularities on used parts.

kev.e

Ok thank,s for the response Retroranger and Bill