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-   -   4.0 vs.4.7 (http://www.jeepgarage.org/f196/4-0-vs-4-7-a-14065.html)

Gn300 10-17-2010 07:24 PM

4.0 vs.4.7
 
We all know how rock solid a good 4.0 is.

How does a 4.7 compare ?

reliability wise and maintenance are they a timing belt or chain ...interface or no.

Chaoul1 10-17-2010 09:22 PM

Re: 4.0 vs.4.7
 
The 4.7L IMO is a reliable engine if you take care of it. Except for that damn Exhaust Mani problem.

I don't know if you can compare it to the 4.0L. IMO the 4.0L is the best and most reliable engine I have ever had.

vicpick58 10-18-2010 10:14 AM

Re: 4.0 vs.4.7
 
I put 281k miles on my 2000 4.7 and never had any mechanical problems with it. In fact it was still running good and passed CA smog inspection when I sold it.

The 4.7 has timing chains NOT belts.

Also the 45/545RFE transmission that is used with the 4.7 is very reliable too. I never had any problems with it in 281k miles.

I now have 160k on my 2004 4.7HO and the only mechanical problem has been the exhaust manifold bolt.

If you keep the oil changed and don't let it ever overheat, I think the 4.7 engine is an excellent choice for reliability.

I have never had the 4.0 engine, but I did have the 42RE transmisssion in a 97 Dakota, it failed at around 90k miles so I am not too impressed with that transmission.

kevinswj 10-19-2010 06:25 AM

Re: 4.0 vs.4.7
 
My wj has the 4.0 and 212000 kms no issues. My brother in law has the 4.7 HO in his overland 200000 ish also no problems. But he has a lot more power and the same mileage. If I had the choice again I would choose the 4.7. Why not have the extra power if there is no extra cost? Just my two cents

StoneCold 10-19-2010 07:07 AM

Re: 4.0 vs.4.7
 
I have a 4.0HO XJ 136,000 and no mechanical probs. I also have the 4.7 in my WJ and no major probs either:thumbsup:

cheapjeep 10-19-2010 11:29 AM

Re: 4.0 vs.4.7
 
I've had a couple of 4.7s(one in my WJ 59,000,one in a Durango102,000)A 318(in my
old ZJ 205,000)and a 4.0(wifes WJ 222,000)and I just think that the newer motors require alot more TLC than the old 5.2 or 4.0. I guess time will tell but I,ve had some
problems with 4.7s that shouldn't of happened at 30 or 40.000 mi. Dont get me wrong I wouldn't trade my HO for anything 'cept maybe a Hemi but they just seem higher strung than the old motors.

JeepMe 10-19-2010 12:06 PM

Re: 4.0 vs.4.7
 
Quote:

Originally Posted by cheapjeep (Post 287190)
I've had a couple of 4.7s(one in my WJ 59,000,one in a Durango102,000)A 318(in my
old ZJ 205,000)and a 4.0(wifes WJ 222,000)and I just think that the newer motors require alot more TLC than the old 5.2 or 4.0. I guess time will tell but I,ve had some
problems with 4.7s that shouldn't of happened at 30 or 40.000 mi. Dont get me wrong I wouldn't trade my HO for anything 'cept maybe a Hemi but they just seem higher strung than the old motors.

I think this is the key here. With proper care, new motors will last a LONG time. The 4.0 seems to have less minor issues happen during the lifetime.

cheapjeep 10-19-2010 12:38 PM

Re: 4.0 vs.4.7
 
One thing I have noticed though is I almost always get better gas mi
in my 4.7 over my wife's 4.0. She has a rough time with that.:lol::lol:
14 to 15 mpg avg 4.0 vs 15 to 16 mpg avg HO. What do you guys get?

jeepnjeep 10-19-2010 02:16 PM

Re: 4.0 vs.4.7
 
The 4.0 in my '93 ZJ was as dependable as a rock. 150,000 miles on it and no troubles at all. Never burned oil nothing. Great engine. So far my 4.7 with 51,000 miles has been fine. I've been lucky with the manifold bolts so far but here's hoping on that one! My buddy had a Durango with the 4.7 and overheated with about 120,000 miles on it. It was never the same after that and had constant head gasket problems even after getting a new head. Keep it cool!

JeepMe 10-19-2010 02:18 PM

Re: 4.0 vs.4.7
 
Quote:

Originally Posted by cheapjeep (Post 287223)
One thing I have noticed though is I almost always get better gas mi
in my 4.7 over my wife's 4.0. She has a rough time with that.:lol::lol:
14 to 15 mpg avg 4.0 vs 15 to 16 mpg avg HO. What do you guys get?

Damn, that sucks. I get about 19mpg when I drive around town. Most of my driving is to work and back (about 75% highway and 25% city). I get 22-23mpg. When I drove all interstate to Columbus I got 26.5mpg.

NHWK05 10-19-2010 09:43 PM

Re: 4.0 vs.4.7
 
The 4.0 is a rock solid engine, ive had 6 jeeps with them and they are all solid engines. The biggest down fall is they are a gas hog, my 05 4.7 gets better gas mileage then any of my 4.0s did. I miss my 4.0, i wish the wk came with it.

If i had it my way i would buy a good used 4.0HO WJ and give my wife my 4.7 Wk and never look back, but i am and always will be a die hard 4.0 fan. To me nothing compares because of the reliability, torque and available market for repair/upgrades. Yea its only 190 hp stock but its not all about HP. I loved my 4.0s, I like my 4.7.

kevinswj 10-20-2010 10:35 AM

Re: 4.0 vs.4.7
 
Quote:

Originally Posted by cheapjeep (Post 287223)
One thing I have noticed though is I almost always get better gas mi
in my 4.7 over my wife's 4.0. She has a rough time with that.:lol::lol:
14 to 15 mpg avg 4.0 vs 15 to 16 mpg avg HO. What do you guys get?

I average around 15 city 20 highway in my 4.0 my brother in law gets 16/23 in his 4.7 HO ( these are light foot figures it all goes down hill fast if you are in a hurry )


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