Dusty.Rose

I just changed my oil and was told I needed to add Lucas Oil Additive with zinc oxide. I did not because the oil will need changed in a couple weeks and if needed I will add it then. Has anyone used this before? Should I put it in or not? it's an '89 4 litre. I use it for to and from work and some very light off roading.

Also, I was told that it should hold about 4 quarts of oil by one person and put 5 in tonight and told it needs another one. How many?

blonde who knows nothing about cars here...

1991Jeep_Man

You're 4.0 holds app. 6 qts. Im hesitant to give a review on Lucas. I added their heavy duty oil stabalizer to my oil when I changed it. At first, the results were great. Engine was quieter, pressure was great... and then out of nowhere, literally overnight, I now have a low pressure issue. Not dangerous low, within spec, but enough to concern me. I'm still trying to establish if it's a sending unit issue though.

The VooDoo Reverend

Don't waste your money. Use Mobil 1 10w30 every 3000 miles, 5 and a half quarts.

If you want to add something, use Marvel Mystery Oil, replace a quart of oil with a large bottle.

You're either getting milked for more money, or someone's trying too hard to impress you with their vast oil change knowledge.

crystalion

I run the Mobil-1 Penzoil Platinum or Castrol Edge full syn %W-30W for winter and 10W for summer. Until I did this my oil pressure was all over the place and basically low -now I get about 35psi on Idle and maybe 55 at 2500rpm.

Also using Pure 1 -Mobil 1- or any other GOOD name brand filter. I only have 90K on the motor for a 2000 but she seems to like the synthetics better.

Dusty.Rose

I put in Quakerstate highmileage 10W-30 and some seafoam.
the Lucas was only $11 but I'll take it back tomorrow and it will pay for another 2 quarts. It's got a small leak so I try to always have some extra with me. I'm not sure on the brand of the filter. Napa most likely since that's where I bought it.
The oil in the pan tonight was BLACK and it looked like rust on the dip stick so I'll be changing it in about 2-3 weeks (depending on finances)
any other advice?

The VooDoo Reverend

Filter isn't important. The real difference between Mobil 1 filters and Fram is about 7 dollars. Anyone who tells you otherwise is really just

Just do a change again soon and use a synthetic to make sure it's clean. I use Mobil 1 religiously, but that's just me.

Don't over complicate it.

tjwalker

Good quality oil and filter with the proper viscosity for the environment you are running in, changed at a reasonable interval and you're done. Skip the additives; they generally are not needed.

You do not need to use a synthetic oil. Synthetics are great, but there are plenty of 4.0 engines that have gone 300k and more with conventional oil, which is what I use. it is strictly personal preference.

What is the history of oil changes on this vehicle?? If the oil changes were not performed at a reasonable interval, increase the interval for a while to help clean the engine.

And the 4.0 needs 6 quarts at an oil change. You really should verify your oil level on the dipstick after changing it; that would have told the story............

Dusty.Rose

Silly me took the previous owners word and receipt in hand that the oil had just been changed. Due to the fact that if looked like rust on the dip stick and over heated a week ago due to no oil I have no idea it's history.
I had never done an oil change before and just wanted to be sure on the amount of oil.

My pressure gauge was all over the place today but it did not get hot and I checked it a few times and my level was ok.

WARNING: blonde with a jeep

tjwalker

Your oil pressure will vary quite a bit from cold to warm and when under throttle vs at idle; that is by design.

Below are the oil pressure specs. for the Jeep 4.0

*Not less than 13 psi at HOT idle

*Between 37-75 psi over 1600 rpms

If you are in this range, you are okay!

If you are lower than this, best toconfirm it by temporarily installing a mechanical oil pressure gauge where the oil pressure sending unit currently resides. Low oil pressure oil readings make me a bit nervous. If you are having abnormally high readings, the problem is usually resolved by replacing the oil pressure sending unit.

Enjoy your XJ!

Dusty.Rose

It's still over heating. How hard is it to replace a thermostat?

WARNING: blonde with a jeep

tjwalker

If you're new to maintenance, the best money you can spend is a repair manual. Factory service manual is the best, Chiltons next and Haynes brings up the rear.

You will refer to it many times.

Replacing the thermostat is easy. Use a 195 degree only. I buy my stats from Jeep and also like the Stant SuperStat. SEARCH forums and the web in general and you'll find lots of information on how-to.

Dusty.Rose

It only took me 3 hours but I got it done. put the gasket on the wrong side the first time and had a hell of a time working around the belt for the lower bolt and having the wrong tools for the job but i'm proud to say i did it myself.
it didn't work though. I finally found the leaky hose after looking 5 times today. it was staring me straight in the face. Oh well it needed all the new stuff done anyways she's been neglected. I'll get that replaced tomorrow and then i hope she will be good to go...well except for the u-joint problem. at least that's what i hope it is.

Disoriented Hillbilly

Is it overheating while idling (sitting still) or at highway speeds?

redmuck

try to get a failsafe stat, thats what im gettin,the failsafe stat this weekend cause mine is sticking closed from time to time and a complete clean and flush.

Disoriented Hillbilly

Fyi-fail safes fail. Get a super stant.