What not to buy ?

[qwertydog]

Hi, I am seriously looking for a good used Cherokee. As with any vehicle there may be one or two years (or models) to avoid, I want the 4.0 straight six and automatic trans. I have looked at the ads and my budget will get me one in the '97 to 2000 year range. Any input on this would be a great help before I part with my hard earned cash. I know Chrysler started building crap after 2000, so I hope an older Cherokee will be a good buy. Thank you for any advice.

[corbinwaterski]

With the auto trannies, you want to look for the Aisin models. I don't have the model numbers on hand, however they are the ones you want. I believe they are used years 1999-2001. Someone correct me if I am wrong. Good luck.

[fredjacksonsan]

The 99 and 00 4.0 engines were built with a defective head that cracks and starts to leak at about 80 or 90k miles. It seems like a head gasket defect, and you can get coolant in the oil or loss of coolant through the cylinders. This only shows up after the vehicle gets really hot; if you just go on a short test drive you might not see it.

The bad heads have "0331" stamped on the side of the head, underneath where the intake and exhaust manifolds are. The solution is to get a pre-99 head from a junkyard and have it installed, junking the 0331.

Other that that I don't know of any issues with particular years...but since the cooling systems on these degrade without maintenance, you'll want to have a good look inside the radiator for corrosion, and keep an eye on the temp gauge for awhile.

[MagicRat]

Yes, avoid the '99 to 01 Cherokees with the 0331 head.

When these heads crack, they are often replaced with heads from pre-'99 engines. If you find one so modified, it may be worth considering.

Otherwise, buy the best-condition Cherokee you can afford. Also, even though Cherokees have had the 4 liter engine and 4 speed Aisin auto trans since 1987, there were many detailed improvements made over the years. So, the newer the model, the better (up to '98, of course)

[wrightz28]

Originally Posted by fredjacksonsan

but since the cooling systems on these degrade without maintenance, you'll want to have a good look inside the radiator for corrosion, and keep an eye on the temp gauge for awhile.

Word, having this problem with a 98 (little hard to look in the radiator tho whent the filler neck is on a 90 degree angle, lol ). It's also my understanding that the 90-94 short blocks are the preferred motor, as the "high outputs", I have a 94 block in my 98.

[2000izusu]

correction guys 00-01 only have the 0331 heads. 99 has the good 0630 head. now the grand cherokee is a different story. in the grand they started using the 0331 head in 99.

check the head casting # above the intake manifold (drivers side) cast right into the head between the manifold and the valve cover.

also another quicky tip. if the 4.0L has a disributor it has the 0630 if it has the coil packs it is the 0331 head. mike

[fredjacksonsan]

Originally Posted by 2000izusu

correction guys 00-01 only have the 0331 heads. 99 has the good 0630 head. now the grand cherokee is a different story. in the grand they started using the 0331 head in 99.

check the head casting # above the intake manifold (drivers side) cast right into the head between the manifold and the valve cover.

also another quicky tip. if the 4.0L has a disributor it has the 0630 if it has the coil packs it is the 0331 head. mike

Yeah, they made the transition a little earlier in the GC, but there is still the possibility of the 0331 in a 99. Best to check before buying!

[qwertydog]

Hey Guys, this is exactly the type of information I need ! When it comes to asking for advice this forum has never let me down, if it was not for your input I would never had known about those bad heads. Perfect ! Many, many thanks. You guys rock !

[LittleHoov]

As far as automatics are concerned the Aisin AW4 should be behind every 4.0 from 87-01. It had a few differences throughout the years, but is still the same basic thing all the way through.

You will find the 4.0 in most every Cherokee from 87-01, 87 was the first year.

87-90 engines use a "Renix" fuel injection system, I honestly dont know much about it, I do know it can be hard to troubleshoot because it basically has no diagnostic system.

As far as the 4.0 goes, here are stock specs copied from another forum:

4.0L I6 EFI "Power Tech" - 177 hp @ 4750 rpm, 220 ft lb @ 4000 rpm - used 87-90
4.0L I6 MPI "Power Tech HO" (High Output) - 190 hp @ 4750 rpm, 220 ft lb @ 4,000 rpm - used in 91-95 and updated in 96-01 to 225 ft lb torque @ 3000 rpm (00-01 models use a distributorless ignition system)

I do agree that the 97-01 models are better looking, which is probably why youve narrowed it down to that. Although theres nothing wrong with the older ones, and Ive seen them look just fine with a few mods. I will say that mine is ugly as sin, but when its covered with mud they all look the same to me!