Diff between 1st and 2nd gen bypass?
12-06-07, 11:08 PM
#1
Diff between 1st and 2nd gen bypass?
I have put a rebuilt S5 into my first gen. (I did not rebuild the engine). It has a a T2 oil pump and high pressure regulator, so I expect the pressure to be high. When I have started the engine the oil pressure is going up over 125psi on start up (my gauge stops at 110 psi).
I have not run the engine long enough to warm up and watch the pressure drop. I posted a thread earlier and got feedback that the pressure was ok. I am still concerned about this pressure and that there may be a oiling problem somewhere that I am missing.
When I installed the engine, I put a 1st gen front cover on the engine with the bypass spring and cap for the 2nd gen in the engine. Could this be causing this major oil pressure spike?
My questions is, is there a significant different between the 1st gen bypass and the 2nd gen? I am concerned that the bypass may not be opening, which is resulting in the high pressure.
Thanks
I have not run the engine long enough to warm up and watch the pressure drop. I posted a thread earlier and got feedback that the pressure was ok. I am still concerned about this pressure and that there may be a oiling problem somewhere that I am missing.
When I installed the engine, I put a 1st gen front cover on the engine with the bypass spring and cap for the 2nd gen in the engine. Could this be causing this major oil pressure spike?
My questions is, is there a significant different between the 1st gen bypass and the 2nd gen? I am concerned that the bypass may not be opening, which is resulting in the high pressure.
Thanks
12-06-07, 11:53 PM
#2
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i think the bypasses are all the same, except the fd, which has a difference spring.
12-07-07, 12:54 AM
#3
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1st gen 12a and 13b front covers have different springs, which front cover did you use? Did you use the apropriate front cover and spring/plunger combination, if you use the 12a front cover and the spring/plunger from the rebuild it might be the problem.
12-07-07, 08:48 PM
#4
Bypass spring for both the S3 and S4 13Bs are the same. Don't have an S5 FSM to refer to. 73 mm (2.87"), btw for the 13Bs. If your running 20/50 oil, it will spike to 125 cold. Warm up the engine and see what it drops to. Changing to 10/30 will drop the cold spike a bit too. Fwiw, the bypass is a safety factor. It's relief pressure is set higher than the ropr. I don't remember the psi, but it's even higher than the upgraded 85 psi ropr.
12-11-07, 10:05 PM
#5
Thank all for your notes.
I put a 12A cover (I am not sure of the year) on the S5 engine to put the engine into my first gen. When I swapped the cover I pulled the plunger, spring, and two washers from the 13B cover and installed it into the 12A cover.
I am also using 5W/30 as a break in oil (and since it is cold here now).
I think my next step will be to put a oil pressure gauge on it and see how high it actually goes. If it goes no higher the 125 psi then I will call it good. But, if it is actually going higher I will have to pull the engine out and take a look.
I put a 12A cover (I am not sure of the year) on the S5 engine to put the engine into my first gen. When I swapped the cover I pulled the plunger, spring, and two washers from the 13B cover and installed it into the 12A cover.
I am also using 5W/30 as a break in oil (and since it is cold here now).
I think my next step will be to put a oil pressure gauge on it and see how high it actually goes. If it goes no higher the 125 psi then I will call it good. But, if it is actually going higher I will have to pull the engine out and take a look.
