So here's the deal...my 305 has 112k on it, runs like a top, nets 25 MPG on the highway at 80, but has a significant oil leak that appears to be coming from the back of the intake gasket and possibly the RH head as well. It would cost me about $750 to have the dealer I work for replace the intake gasket, as well as both head gaskets (while they're in there, its only going to cost about $150 more to do it, so why not???).

The question is, do I even bother? It has 112k on it, and while the leak is an annoyance (drips on the garage floor that aren't always landing on the newspaper I put under it, on the highway it blows out the back and puts tiny specs of oil on my freshly painted back bumper), it isn't critical at this point. I replaced the valve cover gaskets, which cut the leak in half approximately...

I only drive this car for pleasure, about 4-5k miles a year. Do I worry and fix, or drive, enjoy, and save the $$$ for when I rebuild? I'm thinking a Vortec-headed, nicely cammed rebuild will go a long way to making the car more fun to drive...and no, I will not be swapping in a 350. It came with a 305, and it will stay a 305

Thanks to anyone who can help...BTW, are any engine sealer additives worthwhile? I hate putting that crap in it, but if it will stop the leak and buy me a little time, it may be worth it...thanks.

 

why would you bring it to a dealer, you could get it done cheaper somewhere else....

 

I'm not sure why you'd pay $750 for anything at all personally. My 1992 RS running great and only one fender ding only cost me $800. My tranny rebuild didn't cost that much, and it's ready to rumble!

An intake gasket is under $20, takes a few hours, and most of that is waiting for the RTV to dry! Head gasket a little more cash and work, but both gaskets can be done in the driveway in an afternoon for under $75 on parts. Even if you had to buy all the tools, including a torque wrench for the head bolts, and a new Chilton's book for directions, it would still be under $150!

But alas, I'm tight!

Worst case scenerio - you mess it up, pay for a $75 tow to ANY mechanic other than a dealer, and pay him $200 to finish the job. $150 for tools, an afternoon to mess it up, a $75 tow, and $200 to a real mechanic (as opposed to a stealership "technician" - is still half of that stealership price!

Get in there and get your hands dirty! It's too much fun!

 

Hey, I'm all for getting my hands dirty...but to be completely honest with you, I simply don't have the time or the confidence to do this. I work 60 hours a week for the same "stealership" as the sales manager, and all my other time is spent with either my fiance or working on my house...I simply lack the time.

Spending the money, to be honest, isn't the issue here. I have over $8,500 tied up in this car (including the $1,000 purchase price!) to make it look and drive top notch. For me, the issue isn't so much the money as it is a) is it a WASTE of money to fix the leak when I can put that money into a rebuild and b) is it ok to drive it the way it is for awhile?

I know there's a ton of DIY's on here at this point, which is great...when you own an old car, its definitely the better way to go. For me personally, however, I want to spend my time driving this thing...not taking it apart only to find out I screwed something up!!! Headers, exhausts, bolt ons? Sure...love doing that stuff. Tearing the whole top end off? Makes me nervous...

Just out of curiosity, what SHOULD a private mechanic charge for total labor hours for this job? I went through the labor book with my Service Manager, and the total was about 14 hours!!! That quote was with my discount BTW, which is $47/hr...

 

14 hours. lol how many breaks r they taking? I just did it yesterday, took 3 hours, and i was taking my time.

 

Sounds to me like you are not even sure where your engine is leaking. Why don`t you figure that out first? If it is leaking from the back near the firewall, older GM had the oil pressure sender located there and they frequently leaked, easy fix. With 112k miles you do not want to pull your heads, leave it alone. I got lazy with my El Camino when it developed an oil leak at the back of the intake so I let it cool off then cleaned it well with degreaser and forced some gasket sealer in the gap between the block and intake manifold and let it dry overnight and still going 100k later, no leaks. I`ll fix your leak for $750.

 

Sorry to double post. The dealer uses the "flat rate" manual. It lists all possible jobs you can do on a car and lists the hours it should take to do them and that is how you are charged. In my experience, most of the time you get charged 3 - 4 times what the job actually takes, I first became aware of this in the late `60s.

 

I know all about the dreaded flat rate manual...hence why I want to hear from someone experienced on here as to how much it actually SHOULD take for an intake gasket...can it really be done in 3 hours? Seems awful short!! Anyway, I'll admit the one time I've been under it recently was to do a quick oil change and take off with it...so I didn't sit there and really analyze. I tend to trust the guys I work with, despite my hatred of the book...

They said its leaking down the RH side of the block, which makes sense based on where it leaves spots. They said they can see clearly where the intake is leaking, but are not 100% sure if the RH head is leaking as well because of the nature of the leak. The way it looked before made me believe it was all from the valve cover gaskets, which is why I changed those myself...

Gasket sealer on the outside of the block, eh? Interesting...

 

Are you sure they didn't quote you the shop time to do this on a tuned port motor instead of a throttle body? 14 hours labor is ludicrous. Even on a TPI motor, it can be done a lot faster than that. I realize you probably don't want to hurt the other guys feelings at work since they're your pals, but your really need to take it to a privately owned repair shop and have an old school mechanic fix it for a fraction of that price. It's pretty sad that they'd cornhole one of their own employees for that kinda cash to do an intake gasket change! As far as your question regarding sealer on the outside of engine block, did you know that on our years of engines, GM itself actually used straight rtv instead of gaskets to seal the front and back of the intake manifold? The way jimdutro suggested is a perfectly acceptable way to fix it too since all you're doing is building up the original rtv back there some to stop the leak. Plus, you can do that for next to nothing in about 10 minutes. Just make sure to degrease the area really good by spraying brake parts cleaner on it, then blow it dry with compressed air before applying sealant. As far as sealer goes, I wholeheartedly recommend using Permatex's "The Right Stuff", it works fantastic. Just use your finger and smear a good amount on there, then let it set up overnight, or at least a couple of hours before running the motor again. While spending that kind of money doesn't seem to bother you, it's still asinine to pay that much to fix such a simple problem. Why keep spending money for more oil and having a messy driveway when you can spend about 15 bucks for some "Right Stuff" and a can of brake parts cleaner, and eliminate the problem altogether?

 

Hey, I certainly don't mean to act like I have money to toss around...I don't. All that I meant was that for me, if spending that kind of money was what it took to make the car right, I'd live with it if it made sense...I drive the car, I love the car, and I will never part with it. WIth that being said, if its as easy as you say, I'll give it a shot for sure...

Here's a question though, and consider the fact I'm a pretty significant novice when it comes to turning wrenches...what the hell am I actually LOOKING for? I can see on the RH side of the engine where the valve cover gasket once leaked, and that the head may indeed be seeping, but its hard to say. As for the back of the engine at the intake seem, I can barely figure out where that seam is, let alone degrease and seal it. I know this sounds dumb because I know what the intake looks like from the top of the engine, but I do have to seal this from under the car, right? Isn't the transmission in the way of reaching up there?

I know this sounds really dumb...any help is really appreciated, as I am sick of this leak. 800 miles now, and down a little over a 1/2 quart...it isn't bad, but it is messy...

 

Been there.
Done that, on the front of an oil pan.
Felt ashamed.
...but dammit, it worked.
Acceptable on a 100K+ mile daily driver.

 

You fix that one by removing the intake and replacing the gaskets that mount it to the heads and the ends of the block (commonly called "end seals" or "china wall seals").

 

It's actually a lot easier to reach the back "seam" of the intake manifold from up top. Locate the base of the distributor, where it goes into the intake manifold, and the seam will be about 1/2" below that.

 

14 hrs sounds like the time to do both head gaskets. Probably be 3-4 hours labor to do the intake on a tbi motor. It's really unlikely that the head gaskets are leaking oil, but it's common for the intakes to leak coolant or oil. Should only cost you about 300 no more then 400 buck to just have the intake done. Just my 2 cents. I'm a tech. at a gm dealer.

 

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