Should I replace Wastegate?

[McDermott]

I drove my friend's 2006, 5.9L 3500 Mega cab (285 tires) with 70k miles, and it responded much faster from a dead stop than my '05 2500 QC short bed (315 tires) with 89k miles. This is just from pulling off the curb, no revving up, no racing.

I've looked around as much as I could, and suspect the turbo wastegate. Has anyone replaced their wastegate? What was the results? I've seen a handful of aftermarket wastegates for the 5.9L turbo. Any better than another?

Rob.

 

[MMeier]

Gearing maybe, he already has a head start since he is running smaller diameter tires then you. takes fuel to make power, not just more boost.

 

[cerberusiam]

Wastegate doesn't have any effect until you hit 30 psi on a stock truck. If it is stuck open you will never make any boost and have massive amounts of black smoke on take off. The WG is not replaceable on the HE351 anyway, you would have to get a different turbo.

The difference between 32.5 inch tire and a 35 inch tire is going to show in throttle reaction beacuse the engine is tuned for the smaller tire.

 

[AH64ID]

Wastegate doesn't have any effect until you hit 30 psi on a stock truck. If it is stuck open you will never make any boost and have massive amounts of black smoke on take off. The WG is not replaceable on the HE351 anyway, you would have to get a different turbo.

The difference between 32.5 inch tire and a 35 inch tire is going to show in throttle reaction beacuse the engine is tuned for the smaller tire.

Exactly, and if the command valve has failed the truck will still make 22-24psi of boost which is enough for full fueling and a very high EGT.

Are you sure his truck isn't tuned?

Tires do make a big difference.

 

[McDermott]

I'll ask him if his 2006 is tuned. He just bought it last year, and I don't recall him saying it was.

Compared to my 2005, his 2006 feels really light (i.e. lots of immediate power) and no appreciable delay in power delivery compared to mine. Oh yeah, additional details: he has a 5" exhaust. Mine is stock. both trucks have cold air intakes. Would exhaust and tires be enough to make that much of a difference?

In my 2005, i feel like the truck needs to begin rolling a bit then the power comes on and it takes off. I can be a truck length into an intersection until RPM's are sufficient to build turbo pressure.

Can't replace / upgrade just the wastegate? Dang. That's disappointing news.

 

[cerberusiam]

A tuner that removes TQ management will make a HUGE difference in throttle reaction. After driving with it reduced going back to stock makes it feel like a dog. Tires and tuner will make the biggest diference. A 5" exhaust will usually reduce spool and make it slow on the go from a stop.

A WG does one thing and one thing only, bleeds boost off when it gets too high. There is no need to replace or upgrade it as it is n't a performance thing. If you want to make more boost and cool the EGT's at higher rpms then add a boost fooler, or, a boost elbow and WG controller fooler to take it out of the equation. The engine will still boost and rev normally even if the controller goes bad so bottom end is not affected. If you aren't billowing black smoke all the time ther eis nother wrong with the WG.

 

[McDermott]

I just bought my truck in October 2013 with 81,000 mi. Diesels are new to me. So I appreciate all the feedback.given in the responses. it seems like I need to do more research on how to get the stock turbo to spool faster.

I guess if I feel like burning 1500 to 2000 bucks, I can look into a new turbo. For now though, I love my money well enough to want to keep it and find a cheaper alternative.

also, I'm not billowing black smoke.so my wastegate must be operating. I was concerned that it may not be holding exhaust pressure long enough to spool up like it should.

 

[SnoKing]

Trade wheels and tires, and see how yours performs.

 

[AH64ID]

There isn't much out there that will spool faster than the stock turbo, you can thank the emissions based turbo housing for that. A lot of spool is based on OEM tuning.

A mild tune, like a Smarty Jr, will do wonders.

 

[McDermott]

Well, to follow up: I put on a set of Cooper Discoverer ATP's (from Discount Tire). They are 285/70-17's. It did make a difference. The truck does not feel like such a dog when it starts out (like it did when I had 315's on it). I hope my fuel mileage in town will improve. It was at 12 or so. Highway mileage will suffer though, as there is a noticeable increase in RPM at 70-75 mph, so I anticipate loosing mpg. With the 315's, my highway MPG was around 14 or 15 unloaded. The computer shows like 19 or 20. Not even close to the real deal.

I'll look at a smarty as recommended. Oh yeah, I learned that the BFG KO AT's no longer have a mileage warranty. Crazy. Since mine were circa 2011 and suffering from cracking, I'll never put BFG's on my truck again. If BFG won't stand behind them, I'm not putting a dime into BFG's again. The Coopers have a 55k mileage warranty.

 

[AH64ID]

Rpms doesn't always mean lower mileage on these HPCRs like they did on older engines, you may be surprised.

 

[Wingate]

Exactly, and if the command valve has failed the truck will still make 22-24psi of boost which is enough for full fueling and a very high EGT.

Are you sure his truck isn't tuned?

Tires do make a big difference.

I had a buddy saying his truck used to peak at 32-34 psi of boost and now only hits about 22 on his gage. Its stock fueling/truck as far as I know. Would he get a CEL for the command valve if its non functioning properly?

 

[cerberusiam]

Yes, he should have a CEL and a P0243 code stored. Mine did but different years, no telling for sure.

 

[Ozymandias]

Mine did not have a CEL with defective Boost Valve, I noticed it first with installation of the Boost Gauge.

Repared it and had new Truck.

 

[McDermott]

Maybe its too early for me, but whats a CEL?

 

[AH64ID]

Check Engine Light.

 

[McDermott]

ug....it was too early!

 

[cerberusiam]

Check Engine Light