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88 XJ Oil Report

wilcharl

wilcharl

NAXJA Forum User
Location
Wash DC
Guys:

Sent my oil off to blackstone labs and got the below back as a report. Should I be concerned. She has around 145,000 miles on her 1988 Renix 100% stock. Everything is operating well and the only thing origional in her fuel/emissions system is the pressure regulator and the egr valve. All other sensors have been replaced at one time or another. She runs like a top and the Renix ECM has no hiccups (no high idles, crank position sensor drama etc...)

She does have Ford Motor Sport fuel injectors (replaced the leak-o-matic Bendix injectors around 1999 with Orange mustang injectors)

I am not very concerned as she only gets driven about 100 miles a month. I change the oil once a year with full synthetic regardless of mileage (about 1200 miles a year) all of her trips are short.


 
Interesting, I use Valvoline VR-1 20-50 on my "flat tappet" engines as it has the needed zinc phosphate to protect the cam and lifters. My 89 4.0L also runs well and I'd like to use this service as well. How much does this cost to do?
 
B5Blue:

The tests are onyl 25.00

Go to www.blackstone-labs.com and they will send you free collection kits. They are great to deal with.
 
Appears, as if you have some piston ring blow by and or leaking head gasket. The numbers arent that far off. Do you know exactly what the noted values are based off of.
 
Their "universal averages" are similar engines at the same mileage ie: other 4.0 engines.

At 25+ years old, I think she is mostly healthy.
 
First off, why did you get the oil analysis? Just curious.....

Are you using any oil between your 1200 mile oil change interval? The CCV system on the older 4.0 engines can get clogged up and usually requires replacement of all hoses/grommets to return full function. Easy and about $60 in parts for all.

I wouldn't be too concerned, certainly if you have no symptoms. With higher mileage engines, signs of a bit of wear along the way are a part of the game and not really an issue. I like Blackstone Labs too and have used them many times, but I don't see anything that I would chase on a 145k engine. Choose your battles.

Enjoy your XJ.
 
Did the test just for grins. With such low annual driving she gets now , I have nothing really to worry about!
 
+1 cleaning up the CCV is a great idea. Agreed with Black Stone on the bit about fuel, but a compression test is always a good thing. Might as well see how the rings are.

What of oil is in this? This is one of the most important things when looking at a UOA.

Since were here I might as well plug for Shell Rotella T6 :D (no I don't work for them, but if you look at UOAs on Bob Is The Oil Guy you'll see that they're one of the lowest-wearing oils in a 4.0)
 
A few questions, and forgive me if they were mentioned and I missed it.

-What weight/brand of oil?
-What temperatures does this Jeep usually see?
-Any hard starts?
-Does it burn oil?

As long as the Jeep gets up to temperature when you run it, the oil should get hot enough to burn off any condensation or fuel in the oil.

I had the Ford injectors in my Jeep, and they leaked down while it sat, causing my fuel pressure to leak down and harder starts.

145k miles isn't too much for a 25 year old vehicle.

Here is my sample from my Jeep using Pennzoil Yellow bottle 5w30:

http://www.bobistheoilguy.com/forum...owflat&Main=193515&Number=2943687#Post2943687
 
jeepkid03 said:
A few questions, and forgive me if they were mentioned and I missed it.

-What weight/brand of oil?
-What temperatures does this Jeep usually see?
-Any hard starts?
-Does it burn oil?

As long as the Jeep gets up to temperature when you run it, the oil should get hot enough to burn off any condensation or fuel in the oil.

I had the Ford injectors in my Jeep, and they leaked down while it sat, causing my fuel pressure to leak down and harder starts.

145k miles isn't too much for a 25 year old vehicle.

Here is my sample from my Jeep using Pennzoil Yellow bottle 5w30:

http://www.bobistheoilguy.com/forum...owflat&Main=193515&Number=2943687#Post2943687
Click to expand...

What do you mean by leaked down while sat and fuel pressure leak down?
 
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jeepkid03 said:
.

I had the Ford injectors in my Jeep, and they leaked down while it sat, causing my fuel pressure to leak down and harder starts.
Click to expand...

I normally perform a leak down test, if it passes then assume the injectors are not leaking.

I can see potentially how prolonged starting and/or incomplete combustion might leak additional fuel that is not being burned off into the engine oil.

What are normal engine running temperatures? 195 to ~200 +/- degs. ?
 
Last edited:
When I installed the Ford injectors, I would lose fuel pressure when the Jeep sat for more than an hour or two. It was almost exactly like the 97+ fuel check valve problem. They caused longer starts unless I cycled the key twice which primed the fuel system. I changed back to stock injectors and no problems since.


Are you asking me about operating temp or the OP?

Mine runs 195-204* according to Scan Gauge II.
 
jeepkid03 said:
When I installed the Ford injectors, I would lose fuel pressure when the Jeep sat for more than an hour or two. It was almost exactly like the 97+ fuel check valve problem. They caused longer starts unless I cycled the key twice which primed the fuel system. I changed back to stock injectors and no problems since.


Are you asking me about operating temp or the OP?

Mine runs 195-204* according to Scan Gauge II.
Click to expand...

That is news for me ... do you think one or more of injectors may have been faulty?

I'm inquiring because I currently have a set of non OE injectors installed and have been thinking of switching back to the OE

What I know about drainback valves ... there are two valves in the fuel pump assembly designed to hold fuel in the fuel line. When starting the engine, fuel line pressure is built using residual fuel for engine start.

What do you mean by OP? the temperatures the scanner reads? Scanners normally read the coolant temperature from the CTS and IAT temperatures.
 
Last edited:
My Scan Gauge II is pretty useful for reading codes and temp, etc. For MPG, you have to calibrate it by the directions, which takes a few trial fill ups. It probably depends on how well you calibrate it. I haven't bothered with mine. It won't just do it automatically.
 
winterbeater said:
My Scan Gauge II is pretty useful for reading codes and temp, etc. For MPG, you have to calibrate it by the directions, which takes a few trial fill ups. It probably depends on how well you calibrate it. I haven't bothered with mine. It won't just do it automatically.
Click to expand...

So basically similar to a scanner with live readout and will do estimated MPG once calibrated?

I read the display is programmable internally from the Scangauge and not from a PC interface?
 
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