Vortec Reliability after MPFI conversion and intake gaskets

[turbog8r]

Hey guys,

I have a 95 GMC 1500 and my TBI has been problem free with 250,000 miles and a 100lb right foot...but I want to get a K5. I've read a lot of threads saying the TBI is more reliable than the vortec, but could a vortec be just as reliable once the SCPI is upgraded to MPFI and some fresh intake gaskets put in? Those 2 things seem to come up the most when comparing the TBI and the vortec.


Thanks!

-turbog8r

 

[grampadirt]

I did the MPFI upgrade on my wife's '99 Burb four and a half years and thousands of miles ago with zero problems.Glad I did it.Still running great with over 180,000 miles.

 

[someotherguy]

Ask yourself the same question a little bit differently. What IS reliability? Isn't it that it should go a few hundred thousand without having to tear into the engine? Isn't it that you shouldn't be required to buy or borrow specialized tools to deal with a repair job (scanner that can read cam retard) that was due to penny-pinchers cheaping out on intake gaskets?

I'm always leery of a small block Vortec that has already had the intake gaskets replaced by a previous owner. You don't know how long they drove it with coolant in the oil (almost every one of them dumps it into the crankcase when it fails), how many times was it run on the ragged edge of overheating due to low coolant, is the oil in it the recommended grade or is it 50W trying to shut up the beginnings of a rod knock due to driving it around with coolant in the oil before they noticed it was bad?

The majority of people simply don't maintain their vehicles, and don't regularly check oil and coolant. I can tell you from my time with the salvage yard I got a LOT more calls looking for Vortec 350's than I did TBI 350's. It's not that my customers had less TBI trucks, far from it; it's just that more of them had knocking Vortecs because of intake gasket failure that wasn't caught in time.

I'd also say the Vortec small block is a lot more prone to no-starts due to marginal fuel pressure. That poppet valve setup is very picky and even just slightly low pressure, won't start.

In terms of GMT400 engine reliability, in my opinion it goes a bit like this, from best to worst:

5.0/5.7 TBI
7.4 TBI
7.4 Vortec
4.3 TBI
5.0/5.7 Vortec
4.3 Vortec
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6.5 turbo diesel WAY down here because it just can't compare to the others at all. Worst GMT400 engine ever.

Not really counting the 6.2 diesel as so few GMT400's came with them. Same with the NA 6.5 diesel.

Richard

 

[Big2500Red]

I did it to mine with 300k now has over 330k. runs great still.

 

[TylerZ281500]

im agreeing with rich on this one,

what is relaible to you? everything as long as its maintained is reliable. for example i bought my truck 3 years ago with some shady work done and a bunch of stuff amiss, after reconnecting the il pressure guage i found it to be very low. i have very little faith in my motor, the supposed rebuilt trans was a hackjob, but after rebuilding it i feel its much more relaible. i of course check my front end, all fluids, tire pressures etc over and over again, and i love my tbi but on the same token, my buddys vortec 98 hs 460k on it, he drives a thousand miles a week sometimes and the truck has taken it and had the ragged piss beaten out of it for that last 13 years or whatever. but its maintained regularly still. on the same token like rich said ive seen an intake gasket pop and a vortec motors washed right out. all depends whose taking care of it more so than mechanical failure.

 

[someotherguy]

I'll also throw in having seen plenty of small block Vortec engines with either one of the starter bolt holes in the block cracked, or even the pad slightly busted, because of kicking back due to near-hydrolock from coolant in the cylinder thanks to failed intake gaskets. Have just about never seen this on a TBI. Once that sucker is busted, nothing but starter blues for the rest of its short life. Yeah some can be rigged, others can not...

Richard

 

[turbog8r]

Thanks for the replies guys! And Richard, thanks for the detailed response. You brought up the effects of the intake gaskets failing that I hadn't thought about...I was looking at a 96 that just had the intake gaskets and water pump replaced, but from what your saying it may have damaged the bearings depending on how long it was run with chocolate milk for oil haha. Maybe I'll take the good experience I've had with my TBI and stick with it...

 

[mistaake]

I'm 2/2 on Vortec 5.7 with bad intake gaskets. And now I have a TBI 5.7 with more miles than the other two and no problem with intake gasket. So, TBI all the way

 

[98sierra4x4]

I have a snortec but I wish I had a tbi. Im all for simplicity


Sent from my 5.7 Vortec powered iPhone 5S using Tapatalk.

 

[Rogue]

I have a '97 5.7 Vortec, however looking back I wish I would have gotten a TBI. Simply because of the intake gaskets that had to get replaced as soon as I got it last year. My hope is they were caught soon enough....only noise it makes is some pistol slap on cooler days right on startup......keeping my fingers crossed.