rear engine seal
GAWKY
12-16-2005, 07:24 PM
I have a 91 1500 w/a 305 with over 275,000 miles and it's rear engine seal is leaking,i was wondering if there is anything i can put in it to temporarly help with the problem until i get the money to fix it? and what type of oil should i be reguarly using?
2000CAYukon
12-16-2005, 07:50 PM
Are you 100% sure that it is the rear main? My 90 K1500 5.7 started to leak oil and I too thought it was the rear main; however, after closer inspection (and some searches on this website) I found that it was the oil filter adapter O-ring that was leaking.
Fel Pro makes a kit (ES72671) that contains the O-Ring and the gasket between the block and oil filter adapter.
The one piece seals do not leak like the earlier 2 piece design.
You can always get some dye and a black light to really be sure where the leak is coming from.
The rear of the intake or the oil sender leaking can also look like the rear main is leaking.
Good Luck.
//2000CAYukon
Fel Pro makes a kit (ES72671) that contains the O-Ring and the gasket between the block and oil filter adapter.
The one piece seals do not leak like the earlier 2 piece design.
You can always get some dye and a black light to really be sure where the leak is coming from.
The rear of the intake or the oil sender leaking can also look like the rear main is leaking.
Good Luck.
//2000CAYukon
GAWKY
12-16-2005, 09:47 PM
when i got the the oil changed :redface: the guy there said it was the rear main, but i haven't got out in looked at it myself, don't really have a place inside to do it and its really cold outside. Thanks for the info though i'll check it out
Crasen
12-17-2005, 06:35 AM
I have a 91 1500 w/a 305 with over 275,000 miles and it's rear engine seal is leaking,i was wondering if there is anything i can put in it to temporarly help with the problem until i get the money to fix it? and what type of oil should i be reguarly using?
Where did you get your oil changed at? I know I wouldn't change a rear main seal based on what a "lube technician" at Jiffy Lube said. I am not saying the person is wrong or that they do not know what they are saying, but what I am saying is consider the source. I would definately look at the backside of the engine for an oil leak, it very well could be a rear main, but it could be something else. would hate to see anyone go through all the hassle of replacing a rear main seal, and it not fix the leak
Where did you get your oil changed at? I know I wouldn't change a rear main seal based on what a "lube technician" at Jiffy Lube said. I am not saying the person is wrong or that they do not know what they are saying, but what I am saying is consider the source. I would definately look at the backside of the engine for an oil leak, it very well could be a rear main, but it could be something else. would hate to see anyone go through all the hassle of replacing a rear main seal, and it not fix the leak
GAWKY
12-17-2005, 07:47 AM
it was at penzoil fast lane oil change, i see what your saying so i'm going make sure that it is the rear main seal before i replace it, and by the way i haven't gotten to look under my truck, but i opened the hood and theres a little oil on the driver's side exhaust manifold if that helps anyone
67malibu
12-17-2005, 10:44 AM
it was at penzoil fast lane oil change, i see what your saying so i'm going make sure that it is the rear main seal before i replace it, and by the way i haven't gotten to look under my truck, but i opened the hood and theres a little oil on the driver's side exhaust manifold if that helps anyone
Oil on the exhaust manifold sounds alot more like a valve cover gasket (unless penzoil made a mess refilling.) If it's been leaking long enough it can make a total mess out of everything underneath. That might make it look like it's coming from somewhere else. These years are known for the aforementioned oil filter gasket leaking and every GM V8 has a valve cover leak at some point in its life. I'd clean off around the valve cover and give it a few days. You can then see if it's the culprit (or one of the culprits.)
Oil on the exhaust manifold sounds alot more like a valve cover gasket (unless penzoil made a mess refilling.) If it's been leaking long enough it can make a total mess out of everything underneath. That might make it look like it's coming from somewhere else. These years are known for the aforementioned oil filter gasket leaking and every GM V8 has a valve cover leak at some point in its life. I'd clean off around the valve cover and give it a few days. You can then see if it's the culprit (or one of the culprits.)
Crasen
12-17-2005, 06:35 PM
I have a 91 1500 w/a 305 with over 275,000 miles and it's rear engine seal is leaking,i was wondering if there is anything i can put in it to temporarly help with the problem until i get the money to fix it? and what type of oil should i be reguarly using?
I agree with 67malibu in either messy oil change or leaking valve cover gaskets. The valve cover gaskets are relatively easy to replace. They can leak due to not being torqued correctly so if they have been removed lately that is where I would start, they are supposed to be torqued to 90 in-lbs, you might also want to look at the top rear part of the engine for a leak, if memeory serves me correctly (which is not always the case) the oil pressure switch is back there but I could be mistaking this for another car.
As for what type of oil you should be using if you still have an owners manual it should say it in their. it will say either 5w30 or 10w30, the viscosity chart I have says 10w30 is preferred for temeratres above 0 degrees and5w30 can be used in temps below but should be avoided if temps exceed 60, asa to what brand you will get nothing but debate out of that one, and we don't want to start the Mobil, Penzoil, Valvaline, Amsoil wars, now if you are referring to the sae type that most people do not look at on the bottle of motor oil it should be atleast SF or SG, incase you don't know it progresses alphebetically so you wouldn't want to use SD or SE but SH or SI would be fine because they would meet the requirements of SF and SG, if that didn't just confuse you
I agree with 67malibu in either messy oil change or leaking valve cover gaskets. The valve cover gaskets are relatively easy to replace. They can leak due to not being torqued correctly so if they have been removed lately that is where I would start, they are supposed to be torqued to 90 in-lbs, you might also want to look at the top rear part of the engine for a leak, if memeory serves me correctly (which is not always the case) the oil pressure switch is back there but I could be mistaking this for another car.
As for what type of oil you should be using if you still have an owners manual it should say it in their. it will say either 5w30 or 10w30, the viscosity chart I have says 10w30 is preferred for temeratres above 0 degrees and5w30 can be used in temps below but should be avoided if temps exceed 60, asa to what brand you will get nothing but debate out of that one, and we don't want to start the Mobil, Penzoil, Valvaline, Amsoil wars, now if you are referring to the sae type that most people do not look at on the bottle of motor oil it should be atleast SF or SG, incase you don't know it progresses alphebetically so you wouldn't want to use SD or SE but SH or SI would be fine because they would meet the requirements of SF and SG, if that didn't just confuse you
GAWKY
12-17-2005, 10:35 PM
one of my friends told me to put some lucas oil in it to help my engine, but i have heard some bad things bout lucas oil:http://www.bobistheoilguy.com/images/lucas/lucas.htm
what are your opinions? i did a quick look under my truck and there was oil all over the oil pan, but from what i could tell the oil pan wasn't leaking, could oil have leaked their from the rear engine seal or another palce? Thanks for the help guys!!!
what are your opinions? i did a quick look under my truck and there was oil all over the oil pan, but from what i could tell the oil pan wasn't leaking, could oil have leaked their from the rear engine seal or another palce? Thanks for the help guys!!!
67malibu
12-18-2005, 03:33 PM
one of my friends told me to put some lucas oil in it to help my engine, but i have heard some bad things bout lucas oil:http://www.bobistheoilguy.com/images/lucas/lucas.htm
what are your opinions? i did a quick look under my truck and there was oil all over the oil pan, but from what i could tell the oil pan wasn't leaking, could oil have leaked their from the rear engine seal or another palce? Thanks for the help guys!!!
The first thing I always do if I'm not sure where a leak is coming from is to go by the car wash. Wash underneath (and carefully in the engine bay) as best you can then look underneath every day or as often as possible to get a better idea where oil is coming from. If the pan is coated with oil, it could be coming from a valve cover, the timing chain cover, back of the intake or the from the oil pan itself (just to name the big possible offenders.) It is hard to tell until you've cleaned it up and let the leak start fresh on messing stuff up. Don't automatically blame the rear seal. I was almost sure my '88 350's rear seal was leaking. I changed the pan gasket instead and it turned out to be leaking at the very back of the pan, making it look like the rear seal.
what are your opinions? i did a quick look under my truck and there was oil all over the oil pan, but from what i could tell the oil pan wasn't leaking, could oil have leaked their from the rear engine seal or another palce? Thanks for the help guys!!!
The first thing I always do if I'm not sure where a leak is coming from is to go by the car wash. Wash underneath (and carefully in the engine bay) as best you can then look underneath every day or as often as possible to get a better idea where oil is coming from. If the pan is coated with oil, it could be coming from a valve cover, the timing chain cover, back of the intake or the from the oil pan itself (just to name the big possible offenders.) It is hard to tell until you've cleaned it up and let the leak start fresh on messing stuff up. Don't automatically blame the rear seal. I was almost sure my '88 350's rear seal was leaking. I changed the pan gasket instead and it turned out to be leaking at the very back of the pan, making it look like the rear seal.
Automotive Network, Inc., Copyright ©2025