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Topic Review (Newest First)
11-19-2012 07:53 PM
crussell85 Snapped this photo on the way to work today
11-02-2012 09:59 PM
crussell85 Okay, I guess I'll replace then even though there is no evidence at all that they are bad since the shop found the problem.
11-02-2012 08:55 PM
cdminter59
Rebuilding top end

The intake gaskets are most likely bad if you are losing antifreeze and cannot find it. Antifreeze is probably leaking into an exhaust port, heating up and evaporating. Is it easy to take the exhaust manifold lose from the heads?
11-02-2012 06:34 PM
crussell85
Quote:
Originally Posted by cdminter59 View Post
Leaking intake manifold gaskets on these cars are common. Just replace the intake manifold gasket and flush the radiator and block. Do not use Dex-Cool antifreeze anymore. It is a fact that the Dex-Cool reacts with the material the intake gaskets are made with. Check out this website full of compliants. 2002 Chevrolet Impala Leaking Coolant, Intake Manifold Gasket Failure | CarComplaints.com
I don't want to tear into the engine and replace gaskets that are fine
11-02-2012 04:47 PM
cdminter59
Rebuilding top end

Leaking intake manifold gaskets on these cars are common. Just replace the intake manifold gasket and flush the radiator and block. Do not use Dex-Cool antifreeze anymore. It is a fact that the Dex-Cool reacts with the material the intake gaskets are made with. Check out this website full of compliants. 2002 Chevrolet Impala Leaking Coolant, Intake Manifold Gasket Failure | CarComplaints.com
11-02-2012 04:23 PM
hcompton
Quote:
Originally Posted by crussell85 View Post
The engines not toast, it runs great, never have to add oil. The car has been really good to me. I took the car to a shop and he ended up tracking it down to some thermostat bypass elbow or something like that. So no internal leaks! Two bills later and a huge sigh of relief and I'll be back on the road with my trusty car, wouldn't trade it for a brand new one!
Sweet deal glad to hear it running good. Just saying if your going to go into the motor at 300k miles you will be in for major over haul. I wouldnt trash the car but if motor goes a replacement is usally the best bet. Unless going for bigger power or its a newer engine with a fault like bad seal.
11-02-2012 04:15 PM
crussell85 The engines not toast, it runs great, never have to add oil. The car has been really good to me. I took the car to a shop and he ended up tracking it down to some thermostat bypass elbow or something like that. So no internal leaks! Two bills later and a huge sigh of relief and I'll be back on the road with my trusty car, wouldn't trade it for a brand new one!
11-02-2012 02:35 PM
hcompton Thats not a hard engine to find get a runner from the junk yard and go. Forget rebuilding it. Not even the dealer wants to rebuild them. Just replace the lump. My local junk yard has ok shop and will install his engines and gurantee the engine for good amount of miles. Not a bad deal if your stuck. At 300k it will cost a crap load of machine work to get right you could get a good runner alot cheaper. Even if you want a new or performance rebuild dont start with the 300 k engine it cost more than a junk yard motor with 100 k on it and only needing bore and simple machine work to be road worthy. Your curent motor is toast. It will need everything once you take it apart.
11-02-2012 11:59 AM
oldbogie
Quote:
Originally Posted by Plaintoast View Post
i wouldn't really consider that proof would you?
to me it sounded like the lower end was already bad. i think the op was referring to the top end rebuild causing the lower end to have problems.
or maybe i just misunderstood your post.
No, not a cause; but rebuilding only the top end made a bad situation way worse. Now there was no ignoring the total situation it all had to be fixed or scrapped.

Bogie
11-01-2012 09:07 PM
crussell85 Yes, the majority of miles were put on the car on the highway cruising at seventy five-eighty with the cruise set most of the time. Maybe I'll just pull into a shop and let them diagnose it. Even if they charge me an hour labor it could be worth it over chasing and hoping.
11-01-2012 08:24 PM
BOBCRMAN@aol.com The 3.8 engine was a GM wonder. They toyed with this motor, changed things for many years. Untill it started lasting too long. Then it was discontinued.

As stated they last many miles. Most are just getting broken in at two hundred thousand.. Most never see more than 3200 rpm. Cruise at under 2000 rpm. The only problems they have is intake plenums/gaskets and head gaskets. Usually at higher miles. This example probably spent a lot of time on I-75 and I-94 racking up the three hundred thou miles in comfort.

These are not 56 Chevrolet engines. They don't have fancy coatings on the valvetrain. It is just GM got it right, finally. Thin rings that don't beat up the ring lands, conform to the cylinders better. Light weight valves and springs. Positive oil controll seals. Fuel injection and OD tranny.

You will usually find the leak is on the back head. Drivers end. Between the coolant passage and the fire ring of the last cylinder. It Brinnells into the casting from heat cycling. Usually only leaks, into cylinder, at running temp at higher speeds.
You can have any auto repair place put a tester on the cooling system. You may be able to rent/borrow a tester from a chain auto store.
11-01-2012 08:19 PM
crussell85 Anyways, the engine runs great just have to keep adding coolant and not really sure where its going. I read somewhere about putting a balloon or rubber glove on the filler hole of the radiator and cranking the engine over and if the balloon blows up then you have combustion pressure going into the cooling system. This sounds kinda froggy, need citation? Bogie, could explain how to do the test you were talking about earlier?
11-01-2012 06:32 PM
Plaintoast
Quote:
Originally Posted by oldbogie View Post
Way back when dinosaurs ruled the earth and I was going to college, I worked in an all night shop in San Luis Obispo. I drew a job one night to do a top end rebuild on a high mileage 55, 265 Chevy. When I got the heads off I could see the pistons moved about as much sideways as they would up and down. I told the foreman that the engine was shot and doing a top end would just make an oil burning, smoker even worse. He said to just get on with it which I did, buttoned it up early in the morning hours took it for a test drive. It left a thick cloud of oil smoke for several miles. I took it back and wrote up a report sheet that basically said rebuilding the top end only made its smoking habit worse. Next day it was gone. Day after that it was back in my stall with instructions to pull it apart and rebuild the bottom end. Did that with an overbore, new pistons and rings, new bearings, etc. Put the heads back on fired it up no smoke no oil consumption beyond what you'd expect for breaking in the rings.

Bogie
i wouldn't really consider that proof would you?
to me it sounded like the lower end was already bad. i think the op was referring to the top end rebuild causing the lower end to have problems.
or maybe i just misunderstood your post.
11-01-2012 06:03 PM
oldbogie
Quote:
Originally Posted by Plaintoast View Post
I've heard this old wives tale for years. even had a shop owner ask me not to do "too" good of a job on a head rebuild citing that very reason.
i have not yet seen any evidence of it being true.
if you think about it, i can understand where that's coming from, but again, I've never seen any proof.
Way back when dinosaurs ruled the earth and I was going to college, I worked in an all night shop in San Luis Obispo. I drew a job one night to do a top end rebuild on a high mileage 55, 265 Chevy. When I got the heads off I could see the pistons moved about as much sideways as they would up and down. I told the foreman that the engine was shot and doing a top end would just make an oil burning, smoker even worse. He said to just get on with it which I did, buttoned it up early in the morning hours took it for a test drive. It left a thick cloud of oil smoke for several miles. I took it back and wrote up a report sheet that basically said rebuilding the top end only made its smoking habit worse. Next day it was gone. Day after that it was back in my stall with instructions to pull it apart and rebuild the bottom end. Did that with an overbore, new pistons and rings, new bearings, etc. Put the heads back on fired it up no smoke no oil consumption beyond what you'd expect for breaking in the rings.

Bogie
11-01-2012 05:31 PM
Plaintoast I've heard this old wives tale for years. even had a shop owner ask me not to do "too" good of a job on a head rebuild citing that very reason.
i have not yet seen any evidence of it being true.
if you think about it, i can understand where that's coming from, but again, I've never seen any proof.
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