99 v6 head gasket leaking. ISO opinions on options.
#1
04-01-2018, 05:50 PM
99 v6 head gasket leaking. ISO opinions on options.
I’ve got a 99 v6 (3800 series 2) with a m5 behind it.
Just noticed a pan gasket leak, so I checked the oil level to make sure it wasn’t low and it’s got the dreaded milky brown color to it. So I’m pretty positive the head gasket is starting to go, no other symptoms yet though.
I'm debating my options, the body has a lot of miles 264k, but supposedly the engine only has about 85k on it.
Really hoping to not put a ton of money into it, only paid 700 bucks for the car to start with. That said, I figure my cheapest option is to fix the head gasket myself.
Next would be to get a different 3800.
Finally, I could swap another motor in. I’ve got a 98 z28 (plan on using the ls1 and tranny out of it for my 48 pickup) but I think if I took the rack and k member off of it I could swap a v8 5.3 or something in fairly easily, and inexpensively if I didn’t have to buy a bunch of other parts
One of those deals where cheap may win out but if the motor swap was ever going to happen now would be the time.
Just noticed a pan gasket leak, so I checked the oil level to make sure it wasn’t low and it’s got the dreaded milky brown color to it. So I’m pretty positive the head gasket is starting to go, no other symptoms yet though.
I'm debating my options, the body has a lot of miles 264k, but supposedly the engine only has about 85k on it.
Really hoping to not put a ton of money into it, only paid 700 bucks for the car to start with. That said, I figure my cheapest option is to fix the head gasket myself.
Next would be to get a different 3800.
Finally, I could swap another motor in. I’ve got a 98 z28 (plan on using the ls1 and tranny out of it for my 48 pickup) but I think if I took the rack and k member off of it I could swap a v8 5.3 or something in fairly easily, and inexpensively if I didn’t have to buy a bunch of other parts
One of those deals where cheap may win out but if the motor swap was ever going to happen now would be the time.
#2
04-01-2018, 06:33 PM
Most likely its the intake gasket. It is a weak spot on any car originally equipped with dexcool. If you drove the car with the coolant in the antifreeze I would not put any work into it. The coolant will turn into a acid and melt the babbit off the bearings and it will deposit the babbit in places you don't want it. You could get lucky and get and the melted babbit may not have hurt anything but that is a lot of work to find out. I have seen in many times, replace intake/head gaskets and 2 weeks late the motor locks up.
You cheapest to a dependable repair will be a used engine. They are cheap and plentiful since you can use the front wheel drive engine up to 2008. Check out the V6 tech sections. There are sticky threads for engine replacements and V8 swaps. If you just want to see about the 5.3 conversion just to the last post, there is a link there with a parts list. I think you will be disappointed. It fairly complicated and your t5 is setup for a V6 isn't going to work. GM never made a T5-LS bell housing, mainly because the T5 was not designed to handle the torque of a real V8.
You cheapest to a dependable repair will be a used engine. They are cheap and plentiful since you can use the front wheel drive engine up to 2008. Check out the V6 tech sections. There are sticky threads for engine replacements and V8 swaps. If you just want to see about the 5.3 conversion just to the last post, there is a link there with a parts list. I think you will be disappointed. It fairly complicated and your t5 is setup for a V6 isn't going to work. GM never made a T5-LS bell housing, mainly because the T5 was not designed to handle the torque of a real V8.
Last edited by Gorn; 04-01-2018 at 06:36 PM.
#3
04-01-2018, 07:35 PM
Most likely its the intake gasket. It is a weak spot on any car originally equipped with dexcool. If you drove the car with the coolant in the antifreeze I would not put any work into it. The coolant will turn into a acid and melt the babbit off the bearings and it will deposit the babbit in places you don't want it. You could get lucky and get and the melted babbit may not have hurt anything but that is a lot of work to find out. I have seen in many times, replace intake/head gaskets and 2 weeks late the motor locks up.
You cheapest to a dependable repair will be a used engine. They are cheap and plentiful since you can use the front wheel drive engine up to 2008. Check out the V6 tech sections. There are sticky threads for engine replacements and V8 swaps. If you just want to see about the 5.3 conversion just to the last post, there is a link there with a parts list. I think you will be disappointed. It fairly complicated and your t5 is setup for a V6 isn't going to work. GM never made a T5-LS bell housing, mainly because the T5 was not designed to handle the torque of a real V8.
You cheapest to a dependable repair will be a used engine. They are cheap and plentiful since you can use the front wheel drive engine up to 2008. Check out the V6 tech sections. There are sticky threads for engine replacements and V8 swaps. If you just want to see about the 5.3 conversion just to the last post, there is a link there with a parts list. I think you will be disappointed. It fairly complicated and your t5 is setup for a V6 isn't going to work. GM never made a T5-LS bell housing, mainly because the T5 was not designed to handle the torque of a real V8.
Ive got less than 2000 miles on it since servicing it, but not sure when it started, always check the oil before trips of any distance but have just been going to work and back lately
#4
04-01-2018, 09:52 PM
That is backwards. Normally when a head gasket blows it is between the cylinder and the coolant passage. This will cause coolant coming out of the tail pipe and wet spark plugs. It can even set a miss fire code in the computer. It is possible that coolant could fill the cylinder and leak passed the rings but a cylinder with that much coolant into it is going to miss and steam like mad out of the tai pipe.
This is not just my opinion, if you go to a parts store and ask for a head gasket test kit they will give you a kit that checks for Hc in your coolant. AKA exhaust gas in your coolant. There test kit can not check if a head gasket blew anyplace else.
It is possible that head gasket could blow between the coolant passage and oil return but I have never seen it and can not even begin to count how many head gaskets I have done. I remember doing 2 different cars in one day. That was a long day.
Now go look at an image of the intake gaskets. The smaller holes that are sealed all around are coolant holes. They can leak to the outside of the engine or the on the inside. If they leak to the outside you won't lose the motor unless it overheats you will see coolant running down the front or back of your engine. If they leak to the inside it runs right into the oil and you lose the motor. GM had a class action law suit against it for intake gaskets failure, they had to cover repairs 10 year/100000 miles.
Intake gasket failure is the biggest killer of 3800's, I would bet 9 out of every 10 engines replaced it due to intake failure. I suggest even with a fine running 2002 3800 if the intake gasket is original replace it. Why risk the motor.
After saying all that if I was pulling the intake on a engine that old I would do the head gaskets anyway so either way the intake is getting a new gasket. I have pulled a head on one of these while its in the car, it is not fun. I would hate to do all that work and have the motor seize two weeks later.
This is not just my opinion, if you go to a parts store and ask for a head gasket test kit they will give you a kit that checks for Hc in your coolant. AKA exhaust gas in your coolant. There test kit can not check if a head gasket blew anyplace else.
It is possible that head gasket could blow between the coolant passage and oil return but I have never seen it and can not even begin to count how many head gaskets I have done. I remember doing 2 different cars in one day. That was a long day.
Now go look at an image of the intake gaskets. The smaller holes that are sealed all around are coolant holes. They can leak to the outside of the engine or the on the inside. If they leak to the outside you won't lose the motor unless it overheats you will see coolant running down the front or back of your engine. If they leak to the inside it runs right into the oil and you lose the motor. GM had a class action law suit against it for intake gaskets failure, they had to cover repairs 10 year/100000 miles.
Intake gasket failure is the biggest killer of 3800's, I would bet 9 out of every 10 engines replaced it due to intake failure. I suggest even with a fine running 2002 3800 if the intake gasket is original replace it. Why risk the motor.
After saying all that if I was pulling the intake on a engine that old I would do the head gaskets anyway so either way the intake is getting a new gasket. I have pulled a head on one of these while its in the car, it is not fun. I would hate to do all that work and have the motor seize two weeks later.
Last edited by Gorn; 04-01-2018 at 10:02 PM.
#5
04-01-2018, 10:13 PM
I must have read that backwards then. So most likely the intake gasket is my problem then, and it’s doable with the engine in the car? I don’t foresee keeping the car forever. Maybe a year or two. So if I could get by fixing the intake gasket, changing all the fluids and driving it until then that’s what I would be most inclined to do. I’ve had it a year already almost and haven’t even put 2000 miles on it so not like it will be seeing a lot of miles any time soon
#6
04-02-2018, 03:23 PM
Intake is a pain compared to some because of the windshield overhang. I would at least pull the plugs, you are looking one or two really clean plugs. That would indicate they are getting steam cleaned. AKA head gasket. With the intake off that is 75% of the work to do head gaskets.
You can go down to the manual sections. There a some years of factory shop manuals. I am sure 3800 intakes replacement search on youtube may give you a good idea what you are getting into.
You can go down to the manual sections. There a some years of factory shop manuals. I am sure 3800 intakes replacement search on youtube may give you a good idea what you are getting into.
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