Allpar Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
1,005 Posts
Discussion Starter · #1 ·
I will (hopefully) be able to actually start and run my engine in the next month or so. Not having any kind of owner's manual, I do not know what the recommended weight oil is. The engine is a 1988 T2 service long block and has the 1987 T2 intake, but a 1989 T2 Garret turbo. I believe I was running 10W-40 in it, and using Royal Purple synthetic.

I'm sure someone on here should have an idea as to OEM recommendations. Thanks!
 

·
Registered
Joined
·
1,819 Posts
5W30 for my 2.5 NA.
 

·
Super Moderator
Joined
·
21,699 Posts
You should be able to find a used owners manual for it to make the car complete. The API motor oil grade rating at the time was SG. Oil ratings and technology have marched on since. We now have SN grade motor oil:
API Engine Oil Classification (at http://www.pqiamerica.com/apiserviceclass.htm )

I have no opinion on Royal Purple as I have never used it and have no inclination to try it or Amsoil products. I have always just used a premium quality grade, conventional motor oil that meets the Chrysler MS standards for the application. The R.P. 10W-30 apparently meets Chrysler MS-6395.

10W-30 was probably what Chrysler would recommend in the late-'80's for most gasoline engine applications.
10W-40 is OK, but seems a little heavy for modern engines in temperate climates. It would help to seal worn rings and valve stems.
5W-30 is a good fuel-saving motor oil weight for all but the warmest temperatures.

The Mopar 4105409AC would be the OEM filter. Use an OEM PCV valve to keep the crankcase clean.
 
  • Like
Reactions: 85lebaront2

·
Registered
Joined
·
8,325 Posts
I ran 10W-30 in my 84 Laser XE Turbo. Just an FYI, if it matters.
 
  • Like
Reactions: 85lebaront2

·
Premium Member
Joined
·
4,969 Posts
I like Rotella 10-W30 becasue of its temperature capabilites, espcially with a turbo. I've been using i t in my Cuda for 20 years. Some people say not to use diesel oil in a gasoline engine with a catalytic converter so this is up to you. TJ runs it in his 88 Pacifica T1 without problems. I wouldn't use it in a present gasoline engine though.
 

·
Registered
Joined
·
1,005 Posts
Discussion Starter · #6 ·
I had gone to 10W-40 due to what I thought was an oil pressure issue. The "gauge" on the digital dash would read lower and lower the longer the car ran. The problem turned out to not be low oil pressure but an electronic issue in the dash. Pressure checked with a mechanical gauge and at the same time using my Fluke 75 DMM to read the voltage on the gray/yellow wire from the sender would show no change in the relationship nor checking only the actual resistance on the sender. Specifically if 20 psi was x volts cold and resistance was y ohms cold, hot those values would still correlate, the bar graph for the "gauge" would fall off almost to the danger mark as the electronics heated up.

My conclusion, and I tried a couple of clusters and several pull-up modules to see if I could pin down or eliminate the problem, was that there was/is a problem in the integration circuit. A similar, but opposite response shows up in the older Ford gauges that used a 5 volt circuit provided by a thermal "regulator", those would over a long drive climb up in readings, occasionally resulting in running out of fuel with 1/8 tank or so showing on the gauge.

I will see what it does with 10W-30. PCV valves, I learned a long time ago to only use the OEM ones on a turbo as the TII and all 1988 up turbos, the valve sees backside pressure under boost conditions.
 
1 - 6 of 6 Posts
Top