98 3.1L top end rebuild (pics)

[kevinb70]

did you drain the block front and back with both drain plugs on the block? front one is a few inches right of the oil filter, the rear is down low near the steering assembly (i think)

might can spot it with a flash light and use one of those parts grabbers to fish it out

not alot in the way of passages, the coolant jacket in the block is one large chamber around all the cylinders. if it fell in there then it should float on out of there, into the lower intake and out the thermostat

make sure you get the steel/rubber intake gasket... MS98....T.

[jeranamo]

I will look at it better with a flashlight tomorrow and see if I can find it. If not, hopefully I will be able to find the block drain plugs.

[kevinb70]

if you are going to prime the oil pump before startup, i used a 8mm (i think) socket on an extension going into a drill. TAPE the socket to the extension so it wont fall off.

NONE of the parts places has the right oil primer drill attachment. You can get the GM V6 V8 primer (one with the cap and sliding barrel on the shaft) you'll have to cut off the end and permanently attach (jb weld) a socket on the end.

if you want to try then, then use your oil pump drive you just removed to determine the exact length of your modded oil primer.


using the socket/extension, you are going to see that you can't get much oil to the lifters. Sometimes the oil will squirt into the holes but you wont get any pressure because you dont have the cap/barrel to contain the oil flow.

[kevinb70]

what i did with lifters, was before inserting them, i removed the clip and cap and disc and filled up with oil, had my thumb over the side hole, reassembled, and put lifter in the block.

if you have any sludging, i recommend cleaning out the lifters. when disassembling, make sure you are in an area where you can find the clip when it bounces off.... careful on the spring/ball bearing at the bottom of the cup. after it's clean, might want to use Throttle Body cleaner (use the straw) and push on the ball bearing a little, and give it a good blast.

[kevinb70]

Argh, that alternator is hard to install....

Cranked, it died (I think the PCM does that on purpose, first crank after battery was disconnected), then it cranked right up. Heard some lifter ticking, which went away.

Woot, didn't forget a single electrical or vacuum connection.

Now she's smoking a bit, curing the paint, right now she's quiet as a whisper, even with the higher flow magnaflow cat. Shifts ok too.

Right now I have just distilled water in the coolant. Low coolant light was on a little too long for me, finally went out after feeding the rad more water. I'm going to add coolant flush tomorrow. Probably 1 - 2 water flushes before I add antifreeze.

Also will add oil flush tomorrow before I change the oil.

Now I need to drive about 80 miles til the PCM has had time to adjust (I suppose the long/short term fuel trim) A car won't pass our emissions test if battery has been disconnected, have to drive it.

[kevinb70]

Low Coolant light keeps going off. I'm going to have to remove the low coolant sensor and clean it. there was a tsb i think about oil getting into cooling system, and creating an insulating film on the sensor, causing it to go off... and i got plenty oil still in the cooling system...

btw the "low coolant sensor" is several inches below rad cap, on passenger side.
not to be confused with the coolant temp sensor, which is on the lower intake, close to the water outlet/tstat.

[kevinb70]

more pics

[kevinb70]

still need to drain enough water to add some prestone coolant flush, drive it a few days. I will probably remove the thermostat when i am ready to flush again. I put the thermostat in b/c I really needed to take it to emissions testing (she passed) to get my tag.... i feared no thermostat would keep it from going closed loop or throw a code.

lumina wouldnt start this morning. needs idle relearn. drove 50 miles, short trips, with no problem until today. went home for lunch, she cranked when i had my foot lightly on the accelerator pedal. cuts off when i left off the pedal. There is a great thread here for idle relearn. jeranamo you may need this after you get your car running. This is the first time I've had to force a relearn on the lumina, she's always relearned on her own.

A/C is dead... clutch not engaging. gonna hook the a/c gauges up and see if that is because there is a low pressure switch preventing the clutch from engaging. Few months ago the a/c was working, i would cycle it every time i occasionally cranked her.

Also upcoming - front brakes. Bought the parts couple years ago before i laid her up. will do outer ball joints since last alignment they said i should replace the driver's side before they could get it aligned well (too much wobble). I hope I got ceramic pads.

[kevinb70]

well she's good to go, idle problem comes and goes. hopefully the last work i do in my undersized 1 car garage.

today did oil change after 180 miles. oil was clean coming out.

and did probably my 3rd 'coolant' drain (I've been using distilled water only). this time I added 1 gallon of plain green (NAPA) antifreeze. still dirty, i'll do complete flush (no thermostat) with garden hose next month after i move in my new house.

put freon in, a/c ice cold. check on it to make sure leak fix worked (may have been dried o-rings since its been sitting a while)

[kevinb70]

she finally threw the 0506 code ... low idle rpm. i been saying that for days........

iac not working when cold, when engine is hot, it frees up some and it idles better, i suppose. brought my measuring calipers to AZ, got a new one popped it in (my old measured above 1 1/8" so i didnt adjust the new iac)

started it up (woops forgot to do key on - key off to reset the new iac) and it idled high. turned off / on. cranked right up at correct idle.

[kevinb70]

post pics of old LIM gasket and head gaskets, each side. 100k on the LIM gasket, 184k on the head gasket. head gasket was swelling around bolt holes and cooling jackets.

also. pointing out where to look for external LIM gasket leaks

[kevinb70]

http://www.automotiveforums.com/vbul...d.php?t=977985
did that earlier this year, pics / the discussion might help

[kevinb70]

her oil is lovely now last change was conventional, bout to go full synthetic on her from now on... sounds like new again, whisper quiet at 55mph, zero engine noise/vibration (inside the cab), feels like im driving a car with the engine off. using only chevron gas to help prevent the disgusting buildup I found on teardown...

dont think i mentioned in my thread, but open both block drain plugs to prevent getting coolant in the cylinders, one by oil filter other near firewall have to feel for it, just on top of the rack and pinion... just opening the front wont drain both banks

felpro still makes the plastic intake gasket, btw make sure yours is the metal version

[ptcfast2]

Originally Posted by kevinb70

her oil is lovely now last change was conventional, bout to go full synthetic on her from now on... sounds like new again, whisper quiet at 55mph, zero engine noise/vibration (inside the cab), feels like im driving a car with the engine off. using only chevron gas to help prevent the disgusting buildup I found on teardown...

dont think i mentioned in my thread, but open both block drain plugs to prevent getting coolant in the cylinders, one by oil filter other near firewall have to feel for it, just on top of the rack and pinion... just opening the front wont drain both banks

felpro still makes the plastic intake gasket, btw make sure yours is the metal version

Spent the past 2 days tearing down the engine and it seems that I wasn't the first to do so on this car...

Moment I took off the plennium the upper intake gaskets disintegrated. I found 3 of the exhaust manifold bolts snapped off (someone carefully hid them in the corner of the heat shields on the rear and front) so I had to get those out. The exhaust gaskets were shot, and the head gaskets were starting to swell a bit. Replaced the head/exhaust gaskets, cleaned up the heads a bit and went after the intakes.

The lower intake had already been replaced with the 2nd GM revision, but the RTV used between the heads was failing and causing part of the leak. Gaskets had seen better days as well (internals were starting to separate) so I replaced them with the metal Felpro one.

Now I'm just waiting for my injectors to get back from Mr. Injector so I can finishing putting the engine back together. Hopefully everything else goes smoothly...

Overall the engine seemed sludge free! Bit of carbon build up on the pistons, but the cylinders looked excellent. It has 223,000 miles on it, so I was expecting much worse considering I've only had the car for the past 50,000 or so.

[ptcfast2]

Your pics/tips really helped out a bunch! Thanks for taking the time to document this!

Anyways, for those interested I have a fun little story about my rebuild...

Finally put everything back together tonight. Engine cranked after the 3rd time (first was a no-go, 2nd was a sputter) and sounded a bit uneven/harsh in general. I let it heat up a bit, and started working on getting the cooling system bled. Bit tougher than normal as a lot of air was in the system.

Turned the car off once I bled it a bit, topped the radiator off, and turned it back on and I heard a collapsed lifter.

I immediatly thought to myself "crap...I don't want to tear this thing down again" I shut the car back off and let it sit for a bit while I thought about what the cause could be (IE: What did I screw up?). Flustered, I started the car back up...and it was still there. I tried one more time after this attempt in hopes it would just go away or something and it did after a few seconds!

Took it for a ride just now and the performance improvement is amazing. Engine is quiet, less vibration, and much better acceleration.