Bigger Pistons an option?

[SgtAbn]

Hi all, is adding bigger pistons an option for our 3.4L V6? please? Does anyone know? I have low compression in cyl #1 and I'm trying to figure out if I need an entire new engine like the dealership is telling me or if I can simply have someone bore out the cylinder and add a bigger piston? Thanks Guys!

 

[Diezel]

Bigger pistons are always an option, unless the bore of the block is too far gone. The rest of the parts and systems needed to deal with larger pistons, will be an entirely different problem to tackle, and doing it right, will get expensive quickly.

Now just the engine part: The cost of a Long Block vs New pistons and the associated machining costs, Long block will likely be cheaper in the long run as well.

 

[Ibrad]

Dealerships usually don't fix parts and pieces of the internals. If they go in and fix a certain part and a different part messes up then they are liable for fixing that part again. Hence the reason they want to install a brand new engine. It's a better gamble is how they look at it. As to your problem the piston could be just fine. You have valves that could be causing low compression along with the injector loosing compression then the spark plug could be loose also. Also the head gasket could be bad. Many other reasons you could have low compression instead of going straight to boring and installing bigger pistons as the only option. If your not able to test for the specific reason your cylinder has low compression I would suggest finding a reputable mechanic far away from the dealer that has the knowledge of pinpointing exactly what the cause of low compression is before allowing the dealer to install a new engine. That is unless you have lots of money and can afford to get rid of upwards of $6000 or more for a dealer installed engine. Keep us updated as to what you decide.

 

[phattyduck]

You need to find out WHY you have low compression on cylinder 1 - it might be a valve issue, rings, etc. - and the bore might be just fine.

That said, rebuilt Toyota engines are never quite as good as a factory engine, so bear that in mind. As soon as you tear it open, things have to be done very carefully with quality components for it to work well for any length of time.

-Charlie

 

[SgtAbn]

Thank you all for your good advice. I'm told by my dealership that a new factory 3.4L V6 for our trucks is no longer available. Does anyone have a reliable source for a quality rebuilt 3.4L please?

 

[T4R2014]

Yeah, I would verify it isn't an issue that could be fixed with a valve adjustment. I guess a half ass way of checking if it's the bore is trying a can of Engine Restore. Run a can and see if compression goes up. If so, get a new engine.

 

[Sparky 97Runner]

Thank you all for your good advice. I'm told by my dealership that a new factory 3.4L V6 for our trucks is no longer available. Does anyone have a reliable source for a quality rebuilt 3.4L please?

Yota1 Performance gets 5 star reviews for their rebuilt 3.4 but they usually have a long lead time because of the high demand. There may be other options depending on your time frame. Did the dealer tell you what was causing the low compression on cylinder 1? That bit of information will help others on the forum point you in the right direction.

 

[HiluxSurf SSR-G]

one option would be to look for importers of JDM engines. the JDM engines normally have less mileage in them compared to the USDM engines for the same model year.

 

[AuSeeker]

Thank you all for your good advice. I'm told by my dealership that a new factory 3.4L V6 for our trucks is no longer available. Does anyone have a reliable source for a quality rebuilt 3.4L please?

This company has an optional 7 year 1,000,000 mile warranty on their engines, they also honor that warranty if the install is DIY, I think they also offer free shipping in the lower 48 states.

Rebuilt and Remanufactured Engines by Powertrain Products

 

[BuffaloBass]

Am about to fire up one i got from these folks.....HENCO EN MEXICO.... which taco toyo 5VZ don't bother me..... had to chase a few bolt holes, but so far LOOKS good. Ask me in a month or so...

Remanufactured Engines & Transmissions | Gearhead Engines

3 yr warranty , but mine has sat uninstalled for almost 2! All the break in lube i slathered on the camshafts is likely gone.

 

[mtbtim]

This company has an optional 7 year 1,000,000 mile warranty on their engines, they also honor that warranty if the install is DIY, I think they also offer free shipping in the lower 48 states.

Rebuilt and Remanufactured Engines by Powertrain Products

That warranty is comical. Who's going to drive 1,000,000 miles within a 7 year period. Basically, they are giving a 7 year warranty, which is pretty amazing. But, I wonder how that warranty works. if you're 6 years in and the engine fails, they're going to give you another rebuilt engine? Seems to good to be true.

 

[turbo8]

To make it to a million miles in 7 years, you would need to drive 391 miles a day. ~143k miles a year. :driving: