Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2001 Jeep Wrangler owners, lightly cleaned up (personal details are redacted by NHTSA).
Another victim of the 2000-2001 Jeep 4.0l cylinder head cracking between cylinders 3 and 4 on the cylinder head. Cracked head has caused many other expensive problems throughout the engine such as (coolant system failure, crankcase bearing failures, oil pump failure, valve stems being warped, etc.) after extensive research and being a part of many online polls this is obviously a problem with jeeps of all models that have the 4.0l inline 6 cylinder heads of these years. The vehicle was in motion when cracked head occurred causing the engine to overheat as well as oil pressure to drop. Also caused malfunction and ruined o2 sensors on vehicle. The cylinder heads in these 2000-2001 jeeps of all models are faulty and it is obvious cause Jeep changed the heads the following year in 2002. They claim that these heads are cracking due to the engine overheating. …
I bought the vehicle in May 07. 2001 Jeep Wrangler sahara with 4.0l. @ months after buying the vehicle I lost oil pressure. Vehicle returned to dealership and the oil pump was replaced. Less than 500 miles I returned the vehicle to said dealer with a nasty internal engine rattle. Dealer replaced collapsed lifter and bent pushrod. Less than 100 miles later vehicle returned to dealer again with the internal noise. Vehicle torn apart and had the camshaft, lifters pushrods replaced. It has been 7500 miles since my last visit. I now have a slow coolant leak that is making its way into the oil system. I have removed the cylinder head and found a crack in the casting. The casting # is 0331. I have spent numerous hours researching this specific casting # and it is notorious for cracking and slowly leaking coolant into the oil system. My Jeep only has 71,000 miles!! …
Had vehicle for three yrs and in December started loosing coolant and couldn't find the leak. I took it to Jeep and told them the head gasket is going . They said they would check it out and later told me it was a airpocket. I picked it up and ran it for another week, still losing fluid. This happened of and on for 3 times. On the 3 time of me taking it back they admitted the head gasket was shot and they had to replace the head. I went to take it home and 1/2 way there my engine started making horrible noises and jerking. I called the dealership and had it towed back the next day. They then told me due to coolant contamination the engine was ruined and had to be replaced witch was covered under warranty. I now have 3410 miles on new engine and it has started making noise. Took it back to Jeep and the will not cover the warranty saying I have water and dirt marks in airbox. …
2001 Jeep tj, 40,000 miles, slowly losing coolant over the course of 4 yrs. Used a pressure tester and verified no external leaks. However, used the same pressure tester with engine running, per the instructions, and the system gradually built pressure from 18 lbs to 25 lbs before I stopped the test. This indicates coolant leaking into the combustion chamber. Currently my oil pressure is good and there is no coolant contamination on the dip stick or under the oil fill cap. At risk (long term) is the internal engine bearings: cam and crankshaft. I found a thread on the internet that covers many Jeep tj owners with the exact same problem of coolant loss. This is all due to a bad batch of cylinder heads with casting # 0331, manufactured from 2000 through 2006.
Tl* the contact owns a 2001 Jeep Wrangler. The contact stated that the engine overheated several times. The vehicle was taken to a local mechanic where the radiator was replaced twice and the engine seal was also replaced however, the failure was not corrected. The vehicle was taken back to the mechanic, who determined that the engine head gasket was cracked, causing pistons 3 and 4 to fail. In addition, the radiator fluid began to drain abnormally. The vehicle was not repaired. The failure mileage was 136,000 and the current mileage was 148,000. ..updated 11/28/12 the consumer stated the engine head was cracked. Updated 12/03/12
I have an 01 Jeep tj Wrangler, I have recently noticed a drop in performance along with slowly vanishing coolant. Several days ago while in traffic, the oil pressure dropped low enough to set off the check engine light. As soon as I began driving again the oil pressure raised high enough to to clear the light. However as soon as I came to the next light the oil pressure dropped and the check engine light came on again. Upon returning home I looked up the symptoms on the internet and it all LED me to a very common cracked head between the 3-4 cylinder. I was all too surprised to find out how extremely common that is.
We purchased a 2001 Jeep Wrangler about two years ago. Back in November, the vehicle began to overheat. Thinking it was the hoses or radiator cap, we replaced both, which stopped it for awhile. In December, it began to leak again, so we replaced the radiator. It is now January and it has begun to leak again. We have ordered a new radiator, but it doesn't appear that the leak is coming from the radiator, and after reading some of the complaints on the internet regarding the 2001 Wrangler, we are afraid it May be a cylinder head. Has there been a recall on this? There seems to be a lot of complaints related to it'
Tl* the contact owns a 2001 Jeep Wrangler. While driving approximately 45 MPH, the engine warning indicator illuminated on the instrument panel. The vehicle was maneuvered to a safe location. The contact noticed the engine overheated and the radiator reservoir was empty. The contact dispensed coolant into the reservoir. The vehicle was taken to an independent mechanic who replaced the blown head gasket. One week after the repair was performed the failure recurred. The vehicle was not further repaired. The manufacturer was not notified of the malfunction. The approximate failure mileage was 90,000.
I bought this used with only 54,000 miles on the engine. Within a year and at 65,000 miles, it began overheating and leaking coolant. My brother thought it was a cracked head or gasket. After tearing the motor apart and sending the head to be checked, two large cracks were found. The casting # is 331. My brother has been trying to find another head for me and was told by one of the sellers that he can't keep the parts in stock due to the high number of demand for this part.
Needed to replace radiator after just 60,000 miles. Then still had problems with radiator fluid leaking without being able to find where it is leaking. Eventually the cylinder head cracked at 80,000 miles. Now it needs a new engine costing me $5,000.
Engine complaints in other Wrangler years
Frequently asked questions
How common are engine problems on the 2001 Jeep Wrangler?
NHTSA has 23 complaints about the engine & cooling of the 2001 Jeep Wrangler, 14% of the model year's 170 complaints. The component named most often is engine (9 mentions).
Is there a recall for 2001 Jeep Wrangler engine problems?
No. NHTSA lists no engine & cooling recall for the 2001 Jeep Wrangler, though it has 3 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2001 Jeep Wrangler engine problems start?
Half of the complaints with a recorded mileage happened before about 82,000 miles.
Is it dangerous?
Owners linked 0 crashes, 2 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.