Question on intake manifold oil leak

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

pedub

Member
Joined
Dec 4, 2020
Posts
32
Reaction score
28
HI Guys, I just had a intake manifold gasket put in, this is a 2000 OBS so it's really a 1999 Z71 5.7, it was leaking from the back China wall, my question is were does the oil come from, is it the oil return holes leaking past the gasket? it's not like the valley is full to the brim with oil rite? on another note, I can't manually shift all the way to low 1, the gear selector/indicator works fine on all the others L2, L3, D, R just wondering if this is normal ? I like to see it in L1 when pulling a boat up the ramp kind of thing. I read a motor trend add on line when this truck was new and it talks about is starting out in 2nd gear and sometimes it seems like it down shifts to first rite out of the gate but not always, this tranny shifts good and I change the fluid when it needs it. thanks
 

tom3

Full Access Member
Joined
Jul 15, 2019
Posts
1,005
Reaction score
1,541
When the engine is running there is oil flowing and splashing all over the place and the pistons actions really make for some turbulent air flow through the crankcase areas. Only thing that leaks worse than oil is antifreeze, have to have perfect sealing for that stuff.
 
OP
OP
pedub

pedub

Member
Joined
Dec 4, 2020
Posts
32
Reaction score
28
When the engine is running there is oil flowing and splashing all over the place and the pistons actions really make for some turbulent air flow through the crankcase areas. Only thing that leaks worse than oil is antifreeze, have to have perfect sealing for that stuff.
Thanks for the reply, when I had the intake manifold gasket replaced they changed the EGR tube, and had a hell of a time getting it out (more money) why would you have to remove the EGR tube from the exhaust manifold in the first place? couldn't you move it out of the way after taking off the end that goes to the intake manifold? did I get screwed? thanks
 

Eman85

Full Access Member
Joined
Apr 18, 2021
Posts
441
Reaction score
652
EGR tubes are as old as the truck and they break easily.
Engines splash a lot of oil in the valley as the cam spins and lifters move and all of the oil from the heads drain back through there. China wall doesn't use a gasket, just RTV so it must not have sealed good. There is also the distributor and the oil sending unit back there so be sure what is leaking.
With the engine off and the drive wheel blocked and the parking brake on go under the truck and have someone move the shift lever while you watch the cable and lever on the transmission. BE CAREFUL AS IT CAN ROLL AND SQUASH YOU, that's my disclaimer to prevent lawsuits. When the shifter is pulled down to low 1 see if it's moving the rans lever. You can pry the cable off of the transmission lever and see if it is moving it to the correct position. Be sure to reconnect the cable and lever before starting the truck, another disclaimer, if the cable is off the transmission might be in a gear but the lever on the column might be in park or neutral and the truck would start in gear. Don't become a Youtube video!
 

YukonGTmaster

Full Access Member
Joined
Mar 18, 2021
Posts
513
Reaction score
942
Thanks for the reply, when I had the intake manifold gasket replaced they changed the EGR tube, and had a hell of a time getting it out (more money) why would you have to remove the EGR tube from the exhaust manifold in the first place? couldn't you move it out of the way after taking off the end that goes to the intake manifold? did I get screwed? thanks
This is my EGR tube, when I carefully removed it.... I bet the guy removing it thought he got screwed! Lol12FE6492-7C14-4D8B-9F1D-254E782F69F5.jpeg97B1D034-8057-4292-A112-36DD8452300C.jpeg
 
OP
OP
pedub

pedub

Member
Joined
Dec 4, 2020
Posts
32
Reaction score
28
Haa thanks for the Pics GT, wow enough said now I see. e-man good info. OR vet I had Tires plus do the work and it don't leak anymore, before the job they put dye in the oil and found it that way. tom3 thanks for the info!
 

Forum statistics

Threads
131,712
Posts
1,855,560
Members
95,944
Latest member
beeswax
Top