Hi Yall Need Help!

Well Hello I am new to the site and coming full boar with a problem. I purchased an 89 XJ 4.0 from a friend. Well of course it is not perfect. I am having a few problems.

1. I am leaking oil out of the breather on valve cover. OEM has a tube going to air filter box. It seems at idle it is fine but really leaks at higher RPM. I have removed valve cover and cleaned it and the parts in it. Could not locate oil return lines to clean them. Any suggestions??

2. I have no power. It seems at take off it is fine then immediately lags off power.

3. With the power issue it seems to not have a passing gear.

Can any one help me:worship: :huh:

One more problem is oil light comes on at idle even when full. Soon as RPM's up, light goes out.

Welcome to the site.

1. Check the rubber grommets, mine were old, used and cracked, leaking alot. When I changed out the fittings, it stopped. There aren't any "oil return lines" on the valve cover. There's a vacuum CCV in the back that goes through the manifold and an "air breather" in the front that goes back thru the air system. No PCV valve.

2. ??

3. ??

That's all I got.

have replaced grommets I am at a loss.

What city are you in?

Waxahachie

oil light - - - - first try new oil pressure switch,cheapest option== get pressure checked with pressure gauge

For the breathing problem, make sure that the little vacuum tube from the rear of the valve cover to the manifold is entirely free of cracks or clogs. It's very sensitive. Sludge can build up inside and constrict the flow. If yours is the original type with 90 degree sharp elbows, you might consider replacing it with the later type which has gentler bends. It seems trivial, but when I did it on my old 87, it cured about 90 percent of the problem.

Was thinking of replacing with aftermarket PCV valve and vacuum hose

Any more ideas???

Get a Cyl compression check...we usually get a little blowby normally.but with a loss of power from pressing the gas and bad oil blowby, you may have a compression issues Oh yeah Im in Galveston,...if you ever coem down here. gimme a shout first...thers a fun wheeling place here.

Thanks. I did find a motor for 200 I might just replace it.

Daddycajun117 said:

Thanks. I did find a motor for 200 I might just replace it.

Click to expand...

Before you go too far, it's worth looking at the crankcase vent system (there's no pcv valve in the XJ, by the way). With no vacuum to pull it out, even a healthy old 4.0 will blow oil all over the place.

I'm surprised 5-90 hasn't hit this thread yet. It might be worth a PM to him if he doesn't show up soon, because he's a connoisseur of Renix Jeeps, and I'm pretty sure he could give you the correct details on vacuum routing and eliminate the guesswork.

just pmed him

Just got to the message traffic of the day...

1) Check and/or clean the CCV lines. Hell - you can get a set of replacements from NAPA (under their Echlin brand) for about $50, and that's usually money well spent. As I recall, I got everything but the MAP sensor line, with three part numbers (yes, you'll need to get all three. Yes, that ~$50 is a total.)

2) Mileage? Automatic, or stick? The first is more important - you've probably got enough miles accumulated that your engine management sensors are getting on. I'm about to renew everything in my 88 (still need to get a HEGO, but I've got everything else...) to improve sensor response. It's all original - save the TPS I replaced last year and the CPS I did about 50Kmiles ago, so it's all due. Should perk things up (even with no moving parts, sensors can "wear" and they'll respond more slowly to changing conditions. You've got 18 years on anything that hasn't been replaced yet...)

3) I'm almost willing to assume that you have an automatic from this one, but I don't like to "assume" or "guess" anything, wherever possible. Besides, the engine issues should be addressed first, since some of them can present as transmission trouble - and the transmission trouble magically "goes away" once the engine is up to scratch.

Got your PM - here's your answer.

do you have thos part #'s or a diagram??

Daddycajun117 said:

do you have thos part #'s or a diagram??

Click to expand...

Not handy - but if you search for my posts on CCV, I know I posted them about a year or so ago (had to buy two sets.) And, I'm sure they've been posted by others as well.

I don't quite have the relationship with my nearest NAPA than I do with the parts house I use (who orders me catalogues as well, and has been indispensable in my research for Swappology,) but they should have no trouble finding them for you. Don't expect them to be on the shelf in the store tho - there isn't enough coverage to use shelf space for them. They'll have to order them from the warehouse - I think mine took three days to show up.

JEEPAUL said:

oil light - - - - first try new oil pressure switch,cheapest option== get pressure checked with pressure gauge

Click to expand...

X2. Since you say oil light, I take it that you have the idiot light cluster, and not the full guage cluster (which would have an oil pressure guage). Definitely hook a mechanical guage up and verify what the pressure is at idle.

If it is in fact low that it is making the light come on, my money would be on a failing oil pump or I believe there's a pick up screen that's with the pump, that could also be clogged. Since you don't list the mileage it's hard to say.

well it has 193000 mi. and is automatic

Cleaned ccv tube again and blew it out with compressor. Also ran an oil cleaner through motor. (wow what a difference that made) Changed oil. and drove around neighborhood. Seems to be fine. I will be able to check in the morning fo leaking oil.

Oil light still comes on. Extinguishes when I accelerate. Weird.

Also still have loss of power between 20 and 45 mph from initial takeoff.

Are you hearing any unusual noises when the oil light comes on? Such as knocking, or any other "being starved for oil" type noises? If not, probably just a faulty sensor...

Daddycajun117 said:

well it has 193000 mi. and is automatic

Cleaned ccv tube again and blew it out with compressor. Also ran an oil cleaner through motor. (wow what a difference that made) Changed oil. and drove around neighborhood. Seems to be fine. I will be able to check in the morning fo leaking oil.

Oil light still comes on. Extinguishes when I accelerate. Weird.

Also still have loss of power between 20 and 45 mph from initial takeoff.

Click to expand...

It's also possible that your TPS has developed a "flat spot" - but that would be more related to engine RPM, and would present in Neutral as well. I had a similar problem with my 88 - once I noted it in all gears, I checked in Neutral - same thing. That eliminates the transmission. Flat spot at all throttle openings? Gotta be a sensor issue.

Changed the TPS - problem went away. Problem solved. If you have an analogue ohmmeter, you may want to check TPS response and see if you have any flat spots. Don't use a digital - the buffer circuit for the display will hide flat spots. Use an analogue - you can see the needle sweep, and there are no buffer circuits. So, you get immediate response at the gage, and you can see any response problems.

As I recall, TPS response is linear, so you should see a smooth, even motion from throttle closed to throttle open. You will need to disconnect the sensor to check resistance - but you don't need the engine running to do that anyhow.