Engine/Transmission (1998.5 - 2002) 24 valve rattle/ tapping, help!

[SCox]

I took a 2001 HO 24 valve 6spd for a test drive today, and noticed it had a rattle or tap during any time I accelerated hard around 2200 rpm), it seemed to happen at the same time as max boost was achieved and it would then dissappear at higher rpms. I can get this truck for way under book and I really want it, but need to know what this might be. (current truck is a 12 valve 97 3500 xtra cab 4x4). It has 62k and i suspect was towed heavy as it has a fith wheel hitch, and hydraulic brake hook up. Truck is in spotless shape other wise. I need advice quick, I have to make my mind up on the truck by tommorrow 10am.



Thanks, Steve

 

[DEZLPWR]

Why would you want to get rid of your 12v and buy a 24v?

 

[SCox]

Ok, what are the pros and cons of owning a 24v, compared to a 12v. I want more power, like the 6spd. Do you guys like the 24 valve truck, or do I stay with my 12v? I'm listening!



Thanks

Steve

 

[Pit Bull]

I like my 24V, but Steve if I had a 12V like yours that is just starting to get broke-in at 97K miles I would keep it and drive the wheels off it. Your 12V should be good for another 500-900K miles. If you have a problem with the auto just up grade it to a DTT or ATS transmission, it has to be cheaper than a new truck. Plus they are having problems with the 6 speed so I don't think this trade will buy you anything. JMHO



PS make sure you fix your KDP in your 12V if you have not already done so

 

[CumminFast]

I have a 24-valve and I am planning to get a 12-valve in the near future. I had alot of problems w/ mine and know a few people that are in my boat. I like the interior of my '99, but I think the 12-valve is cheaper to fix and easier to get hp out of.

 

[Gary - K7GLD]

The 24 valve engine constantly gets a bum rap - seemingly more because it's "popular" than because of any REAL issues - sorta like knocking SUV's is in some groups...



As far as I have been able to determine, the only advantage - and for MOST of us, it's minor - is that the 12 valve engine is slightly cheaper and easier to get EXTREME power increases out of. Now, if you're seriously interested in drag racing or sled pulls, the 12 valve MAY be best for you but in the REAL world, the 24 valve is gonna do everything you want/need it too, and for anything NEAR a normal power increase, will deliver THAT too for the same price ranges the 12 valvers will!



There may be no significant reasons to purposely choose a 24 valve engine over a 12 valve one - other than the HO engine - but there's dern sure NO REASON to AVOID one, either!



Like I said - the 24 valve engine is getting a bum rap - I traded an older 12 valve for my current '02, have NO regrets -and wouldn't have REGARDLESS of the valve count, I truly feel it's a non-issue for the vast majority of us!

 

[Mundgyver]

65,000 on my 24v HO and no problems. Still has the original lift pump and such. Only thing I have replaced so far are the tires. Like any other rig, if you do the standard maintenance and pay attention to what your doing, it will give you reliable trouble free service. I think your worries are misplaced. Just my thoughts. Have fun with what every you decide.

 

[LSMITH]

The tapping you heard is normal. I don't know what it is but they all do it.



The 24V is insanely cheap to get power out of. Injectors and boxes are cheap new and really cheap used. It is also a lot cheaper to get into the 325-350 RWHP range without EGT trouble than even the 12V. Useable power is cheaper for the 24V IMO.



The 24V has one downside, and that is the lack of diagnostic info that the computers provide. You can get it if you have the equipment, but most of us don't. The 12V will not give you that info anyway.



The 24V has one bad trait, and that is the lift pump. Otherwise it is as solid as the 12V.

 

[10-G]

Tappy tap tappin. Thank goodness someone else experienced this.



I had a 96 and loved it. I noticed the tapping you describe in my new HO. I was curious about it also. It is more noticeable when cold.



I just got back from the rockies and got 15 mpg pulling 5,500 lbs. I pulled up Raton pass at 50 mph in fourth gear passing many vehicles that were crapping out in the right lane with their flashers on. A 3500 was one of these. He was pulling an empty gooseneck trailer and was running about 30.



So far so good with my 02. I have 4,000 miles on it. Aint nuthin wrong with a 24 valve,buy buy buy. I dont miss the crap brakes on the 96.

 

[Big_Daddy_T]

12ver

I was considering getting an older 12 to mod out for some serious off roading. The 12vers report better fuel mileage. better than advertised torque in the midrange. imo a better injection pump and lift pump and definitely proven reliability. will i buy a new 24? yes but im waiting for the commonrail to prove fail safe and maybe there will be a camless design in the future. scares me to think camless but the power is definitely there. Diesels are the future. I bet with all the improvements they get 3 pounds engine weight to 1 hp or even 2 pounds per 1hp from the factory. I eagerly anticipate the future of diesel.