Ruining an entire weekend

[tractorman]

I posted a while back about my leaking timing cover- debating whether or not I should fix it. Well, the decision was essentially made for me when I found that my lower intake manifold gaskets were leaking again. I put in some GM stopleak to get me by for a few weeks 'til I had time to fix it- worked great... but not a permanent solution. With Finals over, it was time to tear the ol' Corsica up. I did this job once before (5 years ago)- before recieving my 60-degree-education on this site and through experience...

So I destroyed an entire weekend, and fixed it all. First of all, I'd like to thank Antisieze. I put this neat substance on every single bolt last time I had the engine apart (except for the LIM bolts, which got locktite)... and they all came out like I'd put them in yesterday. Except for the LIM bolts.

The LIM gaskets failed in the usual manner. I only saw external leakage, but once I got the engine apart, I could see that a small amount of coolant had been getting into the oil. The leaking coolant really corroded one bolt up... had a hard time removing it. Ran a tap & die through/over the threads, and all was well.

Now, I don't know what order these pictures will display in, but I included a picture of my alternative to that stupid quick-connect fitting on the heater hose pipe. That thing pisses me off every time I deal with it... it breaks every time I try to remove the pipe, and I gotta pay another $13 for a new one. I put in a 5/8 compression fitting- worked like it was made for it.

The timing cover part of the job went smoothly enough. After removing the wheel, motor mounts, brackets, tensioner, belt, alternator, p/s pump, etc... it came right off. The cover was in good shape- no pitting. The gasket was just old and rotten. Replaced the timing chain and timing damper while I was in there- one of the guides was coming apart. I put some silicon on the oil pan gasket and the bottom of the cover for lube & sealing, and the cover slid back into place easily enough.

I replaced the oil pump drive o-ring with the new & improved GM o-ring. I replaced those leaky plastic valve covers with aluminum ones. And I filled the cooling system with G-05 antifreeze ('cause Dexcool sux). So far it runs good, and it's leak-free.

Thanks for all the info from this site. It made the difference between a mediocre patch job (like I did 5 years ago) and a thorogh job with significant upgrades.

[IsaacHayes]

Makes me happy I've only had good ole green and metal valve covers from the cars purchase.

Did you use the metal LIM gaskets this time?

The quick coupler pisses me off too. Instead of paying for a new one this time I just got an o-ring that was the right size and shoved all the parts back together and put it on. No leaks! the quick disconnect plastic things they sell replacements for but those are of really no use.... Mine broke and it still works cause there is a bolt that holds the metal line into the coupler anyways.

Odd a compression fitting eh? Hmmm.

Edit: Why did you pull the injectors and fuel rail?

[tractorman]

I see your car is a '94. I thought all the '94 engines came with those ill-concieved plastic valve covers. Maybe I was just unlucky. I think this old Corsical also initially came with green antifreeze, but somewhere along the way, somebody put Dexcool in it. By the time I met my wife, the car had 80,000 on it and the cooling system was thoroghly plugged with dex-sludge. You can still see the remnants of it in the coolant ports in that picture.

I used the new metal Felpro gaskets, and am quite confident that I'll never have to do this repair again. I used these on the '01 Lumina, and it's been leak-free and squeaky clean for two years now. I used Detroit Diesel gray RTV for the LIM ends and the T-joints for all these gaskets. It's good stuff... I've seen it hold up for 800,000+ miles in trucks.

I could've removed the vertical LIM bolts with the fuel rail in place- by just flexing the fuel rail slightly to the side. But the wire for the cam sensor ran under the fuel rail- and the plug wouldn't fit through. My choices were to either pull the cam sensor or pull the fuel rail... and the cam sensor was thoroghly stuck- I would've had to break it to remove it. So off came the fuel rail. It was much easier this time since it'd been off only 5-ish years ago, and last time I used some John Deere grease to help the o-rings slide in... helped them slide out, too. I was surprised to find that the lower injector o-rings were already hardened. Not crispy, mind you... but hard enough that I went ahead and replaced them again.

If I had had my electrical connector tools with me (they were at work), then taking that connector apart and slipping the wires through would've also been an option... but at the time, the fuel rail was the path of least resistance.

That's a good point about the quick-connector. In theory, that stupid plastic clip that always breaks isn't even neccesary. Just the same, I'm quite happy so far with my more permanent replacement.

[IsaacHayes]

F(*@#&$(*&#$(*&#$(*#$(*$#*K I clicked a picture and it took me away, and when I hit back the text I had typed was no longer there. I guess FireFox no longer saves it. (*@Q#$@(*#$(*#@(*$#@(

The previous owners dad worked for a GM Dealer, so I'm sure it got metal covers then. My covers are shiny aluminum too, no rough cast.

To remove the LIM and rails together, pull up on the cam sensor by the wires, only way to remove it.. I've done that 4-5 times and the original one still works. Then use 1/4" sockets to get the vertical LIM bolts out, if you need to loosen the 2 bolts holding the rail down and just wiggle it to get it out of your way. Disconnect the fuel lines at the fire wall and move the whole thing out of the way. I re-routed the cam sensor plug last time though so it's not trapped anymore.

They should offer the other plastic innards of the coupler to rebuild it not just the worthless clips that do nothing. I was careful last time not to break those pieces and threw a new o-ring in and was good. What exactly were the parts you used? I thought the LIM threads were 1/2" NPT or something... ??

How come your intake port on your head is so black?? You are running super rich or something?? I have a lot of oil from the PCV and mine don't look like that. Here is a pic of mine with like 190k miles or something at the time.

[tractorman]

I can't say why the intake ports are so black. The car has about 157k miles. It's a thin, oily/sooty coating. The oil/soot is all in the lower and upper intake, too... and it appears to be coming from the PCV valve and/or the EGR port. The car runs good, gets good fuel mileage, and doesn't use any measurable amount of oil... so I'm not really worried about it.

That valve looks amazingly clean for 190k miles. Or are heads recently re-worked? My Corsica's valves are covered with oily/sooty crud. Have you been using injector cleaner or something lately? If so... what brand?

Yes, that hole in the LIM by the thermostat housing is 1/2" NPT. The compression fitting I used was 1/2" NPTM on one end, and 5/8 compression fitting on the other end. The fitting I used this time was actually an air brake compression fitting- available at any heavy truck shop. I did the same thing a few years ago, though, on a '96 Achieva with a compression fitting that I bought in the plumbing dept. at Home Despot. It worked just as well. I prefered the air brake fitting because it was free, though.

[IsaacHayes]

Those heads have never been off the engine. Only thing that is not original on my engine is the lower intake, plenum, and throttle body. Only replaced gaskets are timing chain cover and LIM and up gaskets. Head gaskets are original. That picture was before I put on the large port 3400 lower and 3500 plenum on. The car always ran great even when stock. I pulled a 16.0 1/4 mile when it was stock with the old O2 sensor.

Never used any injector cleaner. I just figure the engine is running good/tuned well. I have no idea how it will fare with the new intakes on though.

Have you replaced the O2 sensor ever? How about the ECT sensor (2 wire ECM one) ?

[tractorman]

Yeah, I replaced my O2 sensor about 10 months ago... and on-highway gas mileage immediately went up to 28mpg (had been 25 for a couple years before that). I've never replaced the coolant temp sensor- haven't seen any reason to do so. Is this a common failure? If I had access to a proper scan tool, then I would just use my infrared temp gun and verify that the sensor is reading properly.

I agree that the EGR valve is a possibility- it makes sense considering the conditions under which this code occurred. The EGR port was clear, though, and the underside of the valve was clean other than a thin layer of soot. I'm keeping my fingers crossed and hoping that this was a one-time occurence... possibly due to some small piece of crud that was dislodged during the repair.

But this is all conjecture unless/until I get an actual code. Since the car runs good and gets good mileage, I won't likely delve deeper into this issue unless the problem recurs. If the light keeps coming on, or the car runs poorly... then I'll look into it.

[IsaacHayes]

If the sender is reading too cold then the engine will dump more fuel. Without being able to scan it you never know.

[JohnnyReb]

That blue sealant looks scary. Glad to see you also used the DDC grey. Good stuff, they also sell a red sealer that only hardens in the absence of air. Great for sealing two flat surfaces. I will say that you might have overdone it with the sealer, alot of it squished out. Be careful that you don't squish a bunch into the inside. It will likely end up stuck in your oil pump pickup.

[tractorman]

Let not yer heart be troubled- I know what I'm doing... and the potential consequences thereof. Let's just say I learn't my lesson about sparing the RTV in this application. I vowed not to make the same mistake this time around.

And you're right about the blue RTV- it WAS scary. When I first replaced the LIM gaskets several years ago, I screwed up with the application of that blue RTV... used too little, and ended up with a leak at the end of the LIM kinda behind the thermostat housing. Lazy ba$tard that I am... I wasn't about to take the intake off again if I didn't have to (and since only the original-style plastic gaskets were available at the time, I correctly prophesied that I'd have to do this job again). So I cleaned the area with some brake cleaner and an air nozzle... packed in and smeared some more of that blue RTV in/around the area. It made a hellofamess... and you're seeing the remnants. But it pretty much stopped the leak for 5 or so years.

This time, I scraped it off all the gasket surfaces and all the places that really matter, but back to that lazy ba$tard thing... I didn't exactly bother to restore the engine's show-room looks. Leak-free is good enough for me... I could care less about a little errant RTV. Ya'll haven't seen pictures of the rest of the car... but a few blue chunks are the least of my concerns.

About that red anaerobic sealant- I actually used some of that around the coolant ports on the front cover gasket. I know that isn't exactly what the stuff is desingned for... but it's a trick I learned a few years ago when rebuilding John Deere water pumps. That red anaerobic (i.e. locktite 509) makes an excellent gasket dressing in applications where you're sealing coolant with a cheap, thin paper gasket.

btw- I've driven the car for several days now... and the check engine light hasn't come one. Still runs good and gets good mileage. Unless proven otherwise, I'm gonna assume that what I saw was the result of some errant piece of crud dislodged during the repair.

[IsaacHayes]

EGR likely. Sometimes it sticks and then is fine again. I wouldn't worry about it.

[JohnnyReb]

anaerobic , glad you could think of that. I had anabolic stuck in my brain all night but knew that wasn't right. DDC (Detroit Diesel Corp.) sells their own brand and if you use it alot its cheaper to buy it from them. Loctite sells it in smaller quantities. I just had to make a comment about the Blue Goo. Got a brother that will spend $5.00 on a tube of it instead of buying a $3.00 gasket and then thinks he needs to use the whole tube, like it might spoil if he saves some. He was banned from my garage until he seeks professional treatment for his Blue Goo addiction.