5.9l Misfire

[Bear_Gibson]

I guess the main thing that concerns me with this misfire is that apparently it doesn't go away until 2500 rpm. Does that point more towards an engine issue? Tps?

Its really hard to say without being there to see it. I doubt its tps. To mee it says valve issue. Go look at it, do the "dollar bill test".

Sent from my E6910 using Tapatalk

 

[Braeden Clark]

Its really hard to say without being there to see it. I doubt its tps. To mee it says valve issue. Go look at it, do the "dollar bill test".

Sent from my E6910 using Tapatalk

One last question... maybe. So if I went to buy new heads I could get remanned ones for $500 or new ones for like $800. Don't the factory heads still get a ton of miles on them, even if they crack? So I could get the cheaper remanned heads and still get good mileage out of them? Basically is it OK to save money and not get brand new heads?

 

[Bear_Gibson]

I bought the cheapest remans I could find. They're still on the truck 5 years later. That's been my experience. I can't guarantee you'll have bad or good luck either way. I think if you don't beat on the truck and take care of it they will most likely last. However, there are always exceptions and unforseen circumstances that can't be seen.

Sent from my E6910 using Tapatalk

 

[DodgeDude99]

Start with the simplest, easiest, & cheapest things first, a tune up - plugs, wires, cap & rotor, cause odds are it needs it either way.
Also these trucks had a TSB back in the day for misfire, the plug wires cross crossing over each other at the distributor caused misfires, the bulletin was to put wire loom on the 1st foot of plug wire & keep them separated to prevent cross arching.

next check the plenum for leaks, and the associated O2 sensor & cat that it typically fawks up.

then the big dollar cylinder head.

 

[olscout]

Stock heads crack between the valves - but that very seldom causes a miss or leak.
Exhaust valve seats on the other hand tend to sink and go bad since they are just induction hardened instead of inserts.
My 01 would miss at idle and run good after 1700 or so rpms - several sunk seats and wiped out guides.

Almost all 5.9 heads will be cracked, 5.2 not quite as much but still very common.

Go aftermarket and the issue is fixed, do not get stock reman heads as they will crack eventually. Doesn't matter which side on the 5.9, both crack.

5.9 is known for valve seat recession, the 5.2 not so much. My 01 with 130k had a 'miss' that ended up being several sunken valves. At that time there was a firm on eBay selling reman heads very reasonably with hardened seats. Do the plenum (I used a heavy duty aluminum replacement for the tin cover) and you'll be fine until the frame rusts in half.

 

[olscout]

If I could find a rust free 99-01 club cab 4x4 with miles like the one you found and a 5.2 I'd be on like Donkey Kong. For the right price I'd pick up the one you're looking at, but I'd probably just go right to the compression test and then probably heads. In mine I tried a set of Reman flow matched injectors first. Didn't hurt anything, but not really needed. Wish somebody would have told me about the heads early on.

As for the transmission, they're not that bad. They're based on the old TF727. Most of the issues stem from the stuff added on in later years like overdrive and electronic controls. The 46RE especially is probably a gold mine for Aamco and some other transmission shops that get one in behaving wonky and sell a rebuild. The governor pressure solenoid is a common problem, replace it with an upgraded type at the first sign of trouble (or when you change fluid), run a big *** add on cooler, synthetic fluid and Lifeguard Silver and you'll get a lot more miles on it.

 

[Braeden Clark]

If I could find a rust free 99-01 club cab 4x4 with miles like the one you found and a 5.2 I'd be on like Donkey Kong. For the right price I'd pick up the one you're looking at, but I'd probably just go right to the compression test and then probably heads. In mine I tried a set of Reman flow matched injectors first. Didn't hurt anything, but not really needed. Wish somebody would have told me about the heads early on.

As for the transmission, they're not that bad. They're based on the old TF727. Most of the issues stem from the stuff added on in later years like overdrive and electronic controls. The 46RE especially is probably a gold mine for Aamco and some other transmission shops that get one in behaving wonky and sell a rebuild. The governor pressure solenoid is a common problem, replace it with an upgraded type at the first sign of trouble (or when you change fluid), run a big *** add on cooler, synthetic fluid and Lifeguard Silver and you'll get a lot more miles on it.

I am going to look at it here soon and most likely will buy it if it is truly rust free and the trans shifts fine. First thing I would do is a compression test and go from there. I found stock remans for $500. I would like to find upgraded ones for cheap but can't. Like you mentioned as far as the trans I would probably add an external cooler and take it to a shop for a full service to make sure everything is working properly (depending on price). Thoughts on the check valve delete thing?

 

[Moparfanatic21]

I really wish the manual trans was more common because I would MUCH rather have that. But they are hard to find

Actually easy to find. I have a few up at my vacation home up there

 

[Moparfanatic21]

I am going to look at it here soon and most likely will buy it if it is truly rust free and the trans shifts fine. First thing I would do is a compression test and go from there. I found stock remans for $500. I would like to find upgraded ones for cheap but can't. Like you mentioned as far as the trans I would probably add an external cooler and take it to a shop for a full service to make sure everything is working properly (depending on price). Thoughts on the check valve delete thing?

I bought EQ heads for a mild motor build and they seemed fine.

 

[Rick Gabler]

You guys have me stressed out now. I bought a brand new 2019 1500 Ram Classic. No issues. Runs great. But it looks like the futures of these trucks are bleak. I’m not mechanical at all. Don’t like driving anything unless it’s smooth and quiet. Should I have bought a different brand truck or year?

 

[Bill Blackmon]

Let me throw my 2 cents worth in. Almost all if not all 5.9 magnum heads will have hairline cracks between the intake and exhaust ports. Some 5.2 will have them but not very often. This is because the ports are so close together. Chrysler knew this but continued to produce them anyway because of the design of the engine. Even new trucks had them when they left the factory. I have a 97 5.9 magnum and I am sure it has cracked heads. I just run a 7 or 9 pound radiator cap and have had no problems. You get about 3 degrees above boiling for each pound of pressure. This would work for most drivers even with towing (I had no problem and I live in the hot and humid south) As long as you do not race or abuse your truck you should have no problems.

 

[RodeoRam]

You guys have me stressed out now. I bought a brand new 2019 1500 Ram Classic. No issues. Runs great. But it looks like the futures of these trucks are bleak. I’m not mechanical at all. Don’t like driving anything unless it’s smooth and quiet. Should I have bought a different brand truck or year?

Don't worry. The OP is talking about a 23 year old truck with a different engine. He's getting all the info he can so that he can make an informed purchase or know when to walk away.

 

[Marshall]

Well I guess I will have to see how bad the miss is and go from there. I would really hope a tune-up would solve the issue.

I have not read all the posts.
A tune up, don't you think the guy would already have done that before he tries to dump his truck.
It had better be damn cheap, as it sounds like you will have to pay for a motor job.
I would walk, unless you know for sure what is going on, and don't fall for a line of B.S.