Author Topic: DIY Auto Repair - Leaky Intake Manifold Gasket? (Read 26298 times)

MoonPilgrim

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DIY Auto Repair - Leaky Intake Manifold Gasket?
« on: November 30, 2012, 01:20:37 PM »
Background: I have zero understanding about how cars work. On a scale of 1 to 10 (ten high), I'd score in the negative territory. We're talking vague awareness that the car has a gas tank, and when that tank is empty, the engine will not work and the car will not go.

That being said, dare I try to fix a leaking intake manifold gasket on a Chevy Blazer on my own? The high repair cost (hundreds and hundreds and hundreds of dollars of labor), compared to the low part cost ($35) is making me think, what the hell? If I thoroughly document what I do, then it shouldn't cost my mechanic that much to find/fix my mistakes--if my "repair" happens to not work.

Those of you who know, is this a bad idea?

PJ

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #1 on: November 30, 2012, 02:46:43 PM »
Background: I have zero understanding about how cars work. On a scale of 1 to 10 (ten high), I'd score in the negative territory. We're talking vague awareness that the car has a gas tank, and when that tank is empty, the engine will not work and the car will not go.

As to your actual question, I have no idea.

Just wanted to say that I resemble that remark. And sorry to hear your car is under the weather.
'To be human you must bear witness to justice. Justice is what love looks like in public."
Dr. Cornel West

matt_g

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #2 on: November 30, 2012, 03:44:46 PM »
Here is a video of someone replacing the lower manifold gasket.

http://youtube.com/watch?v=Wdo7GBNHZuQ

the video looks pretty bad, but it should give you an idea of what's involved.

Rangifer

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #3 on: November 30, 2012, 06:03:10 PM »
That is definitely not a job for a first timer. The reason it costs so much is because it is a lot of work to get to the gasket.

And if it is anything like on some other GM motors, there is a risk of scrapping the engine if you put it back together wrong.

The guy in the video says it took him 3 days to do the whole job. Depending on your job it might be cheaper to just work three extra days and pay the mechanic.
« Last Edit: November 30, 2012, 06:07:28 PM by Rangifer »

paddedhat

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #4 on: December 01, 2012, 06:10:20 PM »
Had a 1999 Tahoe with the classic intake leak. Also had, and have, access to two GM certified mechanics who work for an independent shop. At the time, 2002, it was a really pricey repair. OTOH, their shop made a shit ton of money replacing engines that only lasted a few weeks after other, less qualified shops had done the same work on GM vehicles. The biggest issue is that the mechanic has to meticuliously scrape and clean the top of the block, while being obsessed with keeping ANY debris from dropping into the engine. Let a little bit of trash drop into the motor, and it's all over. I do a lot of work to my own vehicles, but this is one job I would leave to a mechanic that I know is experienced and trustworthy.

Matte

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #5 on: December 02, 2012, 09:16:44 AM »
The intake job on that vehicle is relatively straight forward. I have done it on both the older vortec style like yours and the newer style. You can screw things up big time if you are not careful and clean. Pulling the sensors and throttle cable are not that bad, take pics so you will remember where they go. Gm is great with plugs and wiring, you won't find two identical plugs so your biggest mistake wiring wise is forgetting to plug one back in wich will cause a check engine light and it to run like crap until its plugged in. Use a torque wrench and the specs when re-assembling or it will leak again. Gm has new updated gaskets for these engines that make the intake gasket leak go away. You have to Make sure nothing gets in, I use a shop vac to clean before lifting the manifold off and when cleaning the surface. It's an easy but time consuming operation, the majority of the time spent is disconnecting stuff to get at it. Also change the oil and coolant once you finish, that way if anything did get in you can make sure it's both flushed out and at the correct level.

thurston howell iv

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #6 on: December 02, 2012, 11:55:12 AM »
This is an easy job. The hardest part is getting up the courage to jump in. It will also give you the excuse to buy some tools!!

This difference in cost of parts vs. labor to install is what made me start doing my own work. It's been some trial and error along the way as it is with most things but it's not all that hard and once you do that, you'll feel empowered and be lass afraid to tackle other issues.

I work on all my cars and cars for friends. I do all my own work (save for body work and transmissions). This is not rocket surgery. If you need a hand, shoot me a PM and I'll be happy to walk you through.

BTW, where are you located?


MoonPilgrim

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #7 on: December 03, 2012, 08:42:48 AM »
Assuming I have the chutzpah to give this a shot myself, are there specific tools I need to buy or borrow? I've read through a few tutorials, and it looks like a torque wrench is about the only thing. Is this a universal size, or do I have to figure out exactly which one(s) I'll need?

I'm still back and forth on this--the knowledge will be priceless, but I'm so afraid of screwing it up, and worried about how I'll get around the two weeks that it will probably take me to fix it.

TH4: I'm in SE Michigan.

thurston howell iv

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #8 on: December 03, 2012, 10:35:08 AM »
You will need tools... Consider them to be an investment. They will pay for themselves. Torque wrench? Not totally necessary at this stage.
You will need a good digital camera.
It would be a good idea to have supplemental transportation while you tackle this project as well.

I'm sending you a pm

paddedhat

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #9 on: December 04, 2012, 04:50:37 AM »
You will need tools... Consider them to be an investment. They will pay for themselves. Torque wrench? Not totally necessary at this stage.
You will need a good digital camera.
It would be a good idea to have supplemental transportation while you tackle this project as well.

I'm sending you a pm
Hate to disagree, but hell would freeze over before I replaced an intake gasket without using a torque wrench. Doesn't matter if it's borrowed, or a cheap POS from Harbor Freight, it isn't an option for this repair. Like you pointed out, this is one job that you need to keep surgically clean as you go.

thurston howell iv

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #10 on: December 05, 2012, 11:55:15 AM »
The torque wrench is not necessary until the assembly is being put back together. At this stage, I think there was still the decision as to whether to even tackle it.

While it is ideal to have the tool, it is not necessary. When's the last time you used a torque wrench to properly seat your wheel lugs or for that matter tighten any bolt? (technically, there are specs for all cars and most all of their bolts) The majority of the bolts simply require common sense... How long would it take repair shops if they stopped and checked every single bolt for proper torque specs?

Nevertheless, if a torque wrench is available (you can get a loaner at most of the parts stores), it would be ideal to use it... In the instance of an intake manifold it may require 2 torque wrenches. If you're looking for absolute precision. One for inch pounds and one for foot pounds to be incrementally tightened within the factory specified pattern to achieve the optimum result.

Matte

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #11 on: December 05, 2012, 11:37:17 PM »
The torque wrench is pretty critical for this job, use a 1/4 inch drive one. The newer gm intake manifolds are plastic and in inch lbs. Barbour freight is like 20 bucks for a torque wrench so no excuse.

thurston howell iv

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #12 on: December 06, 2012, 06:05:11 AM »
The OP does not specify the model year of the vehicle. The manifold could be plastic or not. Some of the Blazer intake manifolds need torqued up to 10-11 ft lbs not merely inch lbs. Nevertheless, as I have stated, having a torque wrench to get the proper spec is "ideal" not necessarily "critical". On heads? That's a different story.

The torque wrenches are available as free loaners so there really is no excuse but, that being said the initial reason for mentioning the this in the first place was that the OP had expressed that a torque wrench might be the only thing that would need to be purchased or borrowed and I did not want the OP to be confused and think this would be the only tool needed. Or that this project would not be possible without one. Besides, the free loaner and harbor freight torque wrenches really aren't all that accurate, yet better than nothing. Professional engine builders use the good stuff (ie: very expensive, calibrated wrenches)... However, we're not building a race car here, just swapping a gasket... You guys are making it seem like it's harder than it is.


MoonPilgrim

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Re: DIY Auto Repair - Leaky Intake Manifold Gasket?
« Reply #13 on: December 14, 2012, 10:22:11 AM »
OP here. Model is 2003, I'm borrowing a torque wrench. :)

I'm entering what feels like the home stretch, although it is really just the middle. I'm at the remove intake manifold-clean-replace gasket stage. That will be tomorrow's project.

Fingers crossed, it will come back together on Sunday and be driveable.