Constantine

I've put my life's work into air cooled vw knowledge, decided to quit the hobby and get into Jeeps.
Looking for insight from experienced Jeepers.......
Ok ya'll I have an engine in serious misrepair condition.
Have owned the vehicle for a little over a week.
Oil pressure gauge and coolant temp gauge are not working.
Or the engine isn't heating up, I put a new temp sender on it... not sure yet.
Can't guarantee that it even has a thermostat in it.
Fans come on and off with the key, nothing else effects them.

91 4.0L 192,xxx miles.

What I currently have:
Plugs, wires, cap & rotor.
Oil press. Sender.
Victor reinz valve cover gasket.
Oil & filter.
Air filter.
Fuel filter.
Have those items but haven't installed yet.

02 sensor has the wires pulled out of it, going to get one and replace the full exhaust as well.
Converter is getting extremely hot, muffler pretty hot itself.

Put some seafoam in the tank and drove around some, engine became less chuggy under initial load.

Smokes but only around 1500 rpms and up.
No smoke while idling, no vapor coming from oil fill cap or vent line going to air intake box.

If it were yours, what all would you do to it?
Oh and I'm assuming the check engine light doesn't work bc it's not on.

MayerMR

Ok man, so I'm no pro on Jeep 4.0's or anything, but so far your have a good list going.

Since you know you need to verify that you *have* oil pressure, change the sender ASAP. Next thing to do is get the coolant temp registering. That is most likely electrical in some way shape or fashion. Start easy and look at fuses and grounds.

If it's in disrepair I highly suggest changing all oils/lubs. Which you have on your list already, at least for the engine. I *personally* like to run Shell Rotella oil and Wix filters - they seem to be pretty popular around here as well.

My engine was a complete dog until I did the exhaust. I'm 90% sure my cat was blocked up. It's like a new engine. If I could do it over I would do the exhaust right away. Buy the pre-bent pipe sections from Autozone/where ever and the muffler/cat of your choosing. Then have a shop install and weld it together for durability - though that's my preference.

My '87 Waggie was smoking a little bit and was just generally terrible until I did the new exhaust, oil change, and vacuum line changes. I've also been running Chevron Techron (and/or Chevron w/Techron) fuel since I bought it. I don't get smoke anymore, at all. I work in the industry (downstream) and Chevron/Shell offer the best detergents, but Chevron offers the same amount of detergents at each grade, Shell differs by grade with Premium having the most, of course).

Of course do the the rest of the things you have listed for the tune-up as well. They should all make a pretty good difference assuming you haven't got any serious issues with the head/valves.

Let us know how how the tune up goes.

-Matt

Constantine

I had planed to have all that done by now.
We're experiencing some horrible flooding right now, roads are washed out, children out of school, etc...

Will get to it though.
I forgot to add that I do plan to compression test and possibly perform a leak down test.
Not sure if valve seals can be inspected visually but going to look at them when I do the valve cover gasket.

Also all fluids will be changed on it.
Slave cylinder is a little leaky so clutch will come soon.
Going to pull differential covers and inspect as well.

Thanks for your input, will update as soon as all tasks are done.

MayerMR

Sure thing man.

Where are you? We are getting pissed on here in N. Texas as well, but I hear Louisiana is really struggling.

Look forward to hearing your progress. I've yet to do my compression test because my set didn't have long enough spark plug threads - rented one from Autozone but haven't had a change to check mine yet.

Fingers crossed and good luck to you and your family with the flooding!

-Matt

Constantine

I am in North East Louisiana.
Monroe/ West Monroe are the nearest major cities, which are located along I-20,
I'm about 20 minutes north as the crow flies.

Definately getting deep around here.

Thanks and hope it doesn't get too bad in your area.

Constantine

I was reading in the repair manual....
The coolant temp sender I replaced was on the thermostat housing.
Manual says its down low on the block?
I don't see what it's talking about

MayerMR

I *believe* the one you replaced on the therm housing for a '91 is for the electric fan.

I'm honestly not certain if the sender for the gauge on the 4.0 is on the block, but I know it was on the block of my '75 Scout II - so it's possible.

I'll have to defer to another on this site on where the sender for the gauge is.

Constantine

I just went to O'Reilly auto and had them do a search for coolant temp sender for my vehicle.
We figured out which one it was and I installed it today.
It nows shows a temp after it runs for a few minutes.
It stays on the line between the first line and 210.
What is normal operating temp?

MayerMR

That's great. So now we know your engine is running in a fine temp range. I believe that line is at about 205 degrees. I just did my entire cooling system; radiator, thermostat, water pump, etc. and I run at the same temp, approximately.

See picture:

BillyBoy

GJ with the Info Mayer.

If you're new to jeeping. Check out cruiser54's ground refreshing. As a matter of fact his entire post is Biblical on this forum. The things he has listed cost almost nothing and get an abused jeep into shape fast. A little Elbow grease aside.

Also, I just did the Rotella oil treatment and my engine runs way better. Cost of an oil change, removed 10 years worth of gunk. Wish I did it right when I got it instead of 2 years later.

BillyBoy

BTW. ..

Welcome to the addiction.

Constantine

Alright well good deal.
Although my main concern was making sure it doesn't and wasn't overheating.

I went ahead and ordered a thermostat & gasket, radiator cap.
The 02 sensor, manifold 2 pipe gasket and muffler.
No point in a converter until I can stop it from being stopped up with gunk.

I want to see inside the manifold to see what kind of buildup may be in there with the smoking.
The smoking just isn't consistent enough.

Constantine

I will certainly look for his thread.
This poor old Jeep just hasn't been taken good care of.
It's been someones hunting rig for who knows how long.
This is where she was sitting with a for sale sign in the windsheild.
I just knew she needed me.



It always had a really draggy start and poor charging.
I redid the battery posts and rerouted some of the wiring to the battery yesterday.
Starts really well now and actually gives a good charge to the volt gauge.

Constantine

I'm gettying ready to replace the clutch and would like to replace the rear main and oil pan gasket atleast.
What all is easily accessible seal & gasket wise when I dive into this project?

One thing that I question is, I see Felpro gaskets on the valve cover and oil pan, the blue neoprene style gaskets.
Aka Perma Dry gaskets.
But oil is oozing out everywhere?

denverd1

Check your flex plate for loose bolts. May want to do oil pump while the pan is down. Mine had 200K with a supposed rebuild at 140K. I replaced for cheap insurance. take a look at cylinder walls from the bottom.

with that much oil leaking down the block, another culprit of your slow start could be the contacts on the starter solenoid covered in gunk. easy to clean, but will need to be done semi often until you get your leaks solved.

FYI valve cover gasket is known to leak from the back as well.

Your engine issues aren't major IMO. looks like a good builder. good luck!