[Timbubba]

Hello. I have a 2005 Canyon 4x4 crew cab with 3.5L and auto transmission that has just under 110,000km on it. It's been fairly reliable except last week when I found out that it needs a new head at a cost of $6000. I know I can use a GM 3.7 but can I also use a 3.7 Isuzu engine? Are there any other v6 engine options that will bolt up to the stock transmission?
I'm pissed off that GM didn't issue a recall on the 2004/2005s as my head problems would have discovered.

 

[2005-z71]

Hello. I have a 2005 Canyon 4x4 crew cab with 3.5L and auto transmission that has just under 110,000km on it. It's been fairly reliable except last week when I found out that it needs a new head at a cost of $6000. I know I can use a GM 3.7 but can I also use a 3.7 Isuzu engine? Are there any other v6 engine options that will bolt up to the stock transmission?
I'm pissed off that GM didn't issue a recall on the 2004/2005s as my head problems would have discovered.

the isuzu 3.7 i5 is the same engine as the chevy/gmc if it is a 2007 it should be a direct swap 2008-12 need some modifications. the head issue was covered under an extended warranty that was 7 years or 100,000 miles. the only other engine option would be a v8 they will work with 4l60e trans but you will need a new bellhousing.

also a new head should be about half that i had mine done at a GM dealer with GM parts for about $3000. one member did it himself (he will most likely respond too) and had a valve job for much less then that if you can do the work.

 

[BADLANDER]

There will be a how to posted soon on the 08+ swap

 

[Gold Country Russ]

New head? Not even available anymore. There is nothing wrong with these heads that a competent machine shop can't fix for about $325. A normal valve job and new valve guides are all that is required. Add gasket set, head bolt set, timing set, damper bolt, water pump, filter, and fluids for another $400. If you can't do the R&R then add another $1,200-1,800. for labor.
If you swap motors how will you know it will not have the same problem? GM used the same sub-standard valve guides up until sometime in the '08 production run.

 

[Greg74]

$6000!! Sounds like way too much money for a new head to me too.

 

[Roinas92]

There will be a how to posted soon on the 08+ swap

Already posted

New head? Not even available anymore. There is nothing wrong with these heads that a competent machine shop can't fix for about $325. A normal valve job and new valve guides are all that is required. Add gasket set, head bolt set, timing set, damper bolt, water pump, filter, and fluids for another $400. If you can't do the R&R then add another $1,200-1,800. for labor.
If you swap motors how will you know it will not have the same problem? GM used the same sub-standard valve guides up until sometime in the '08 production run.

Heads were the issue for the 04 and 05 and was corrected by 06.

 

[Roinas92]

Hello. I have a 2005 Canyon 4x4 crew cab with 3.5L and auto transmission that has just under 110,000km on it. It's been fairly reliable except last week when I found out that it needs a new head at a cost of $6000. I know I can use a GM 3.7 but can I also use a 3.7 Isuzu engine? Are there any other v6 engine options that will bolt up to the stock transmission?
I'm pissed off that GM didn't issue a recall on the 2004/2005s as my head problems would have discovered.

The 3.7 was used in the isuzus, colorados, canyons, and hummers and they are all the same engine. Any 3.7 can be made to work in place of your 3.5. If it is an 07 it will be a direct swap.

If it is 08-12 you can follow this how to to convert it to be like an 07:

http://www.355nation.net/forum/how-...nce/193761-how-modify-2008-2012-2-9l-3-7l-engine-swap-into-2004-2006-truck.html

Your other option would be to 4.8, 5.3, 6.0, or 6.2 swap which minimum cost are around 2k or more.

You could also be the first to swap the 3.6 from the 700s in there and be the coolest guy around here lol.

 

[Gold Country Russ]

Already posted



Heads were the issue for the 04 and 05 and was corrected by 06.

Wishful thinking! Here is a short list of fellow 355 members who will disagree. All had 3.7's and the same premature leaking valve problems.
2007: 1bad355, Fixxxerkh202, Collyman07, & 703inthe808.
2008: Jaygold61, Canyon08z71, Dilbottehrobort, Raptor98k, Zexy Magician, & Joecanyon1.

 

[Joe canyon]

Wishful thinking! Here is a short list of fellow 355 members who will disagree. All had 3.7's and the same premature leaking valve problems.
2007: 1bad355, Fixxxerkh202, Collyman07, & 703inthe808.
2008: Jaygold61, Canyon08z71, Dilbottehrobort, Raptor98k, Zexy Magician, & Joncanyon1.

Not

 

[Roinas92]

Wishful thinking! Here is a short list of fellow 355 members who will disagree. All had 3.7's and the same premature leaking valve problems.
2007: 1bad355, Fixxxerkh202, Collyman07, & 703inthe808.
2008: Jaygold61, Canyon08z71, Dilbottehrobort, Raptor98k, Zexy Magician, & Joecanyon1.

There is always going to be a few that will have their own issues. Your list is small in comparison to everyone that owns trucks in those years.

BTW... do you just keep lists of people that have had valve problems for just the hell of it??

 

[Gold Country Russ]

Actually this list is from a single thread I remembered.
http://www.355nation.net/forum/i4-i...um/i4-i5-engine-drivetrain/24064-cylinder-head-problems-3-7l-specific-only.html
I'm sure there are many more if someone wanted to do a real search. I am not going to say that GM didn't make any improvement to the '07-08 valve guides but what ever they did still didn't fully resolve the problem until maybe '09.
If I had any pre-2009 4 or 5 cylinder engine of any mileage out of a truck it surely wouldn't get installed until after a valve job w/ new guides & seals. Personally I have a '04 & have done my valve job so I have no skin in this game.

 

[Timbubba]

Actually this list is from a single thread I remembered.
http://www.355nation.net/forum/i4-i...um/i4-i5-engine-drivetrain/24064-cylinder-head-problems-3-7l-specific-only.html
I'm sure there are many more if someone wanted to do a real search. I am not going to say that GM didn't make any improvement to the '07-08 valve guides but what ever they did still didn't fully resolve the problem until maybe '09.
If I had any pre-2009 4 or 5 cylinder engine of any mileage out of a truck it surely wouldn't get installed until after a valve job w/ new guides & seals. Personally I have a '04 & have done my valve job so I have no skin in this game.

What was wrong with the faulty heads? Was it poor machining, poor casting, or poor parts? Are there any good videos on replacing the 3.5 head for DIY?

 

[Lnhiv]

Bad valve guides. And no there aren't any vids. It's not the type of job you want to tackle if you need any kind of video instruction.

 

[Gold Country Russ]

Just defective valve guides. The good part is that they are fairly cheap and are easily replaceable as part of a valve job. The valve seats and oil seals get damaged because the valve is wiggling around in the guide but the seats are also easily machined as in any valve job.

 

[mgbro]

on the topic of what fits... and hear me out, but why doesn't the 4.3 fit? now the old ones are not exactly ideal, as they are old. but GM relaunched the 4.3 in full size trucks with much better numbers. I'm sure with some searching a wrecked v6 silverado could be found.

Now I'm not a total gear head so that's why I ask (out of curiosity), but if we have a 5.3 like my truck, then why not the 4.3? It's always been known as the 350-2 (cylinders). They are also both 90* configurations so the block shouldn't be much wider. Theoretically to me it "would fit the engine bay" and with modification, mount to the transmission, which is probably the same as the full size trucks. But I'll let somebody that knows tell me what is in the way or which part (probably a computer) doesn't like something.

No I won't defend the 4.3 as a great engine, I know it very well. It's solid as F, but performance is DOA, and modifications are useless, BUT it's solid.

 

[Timbubba]

Bad valve guides. And no there aren't any vids. It's not the type of job you want to tackle if you need any kind of video instruction.

I want to make sure that I'm up to the job before I take it on. I've worked on old era engines but I thought that printed instructions along with videos might be the best but instructions will work, I'll read through them a few times.

 

[Lnhiv]

Just look up how to replace valve guides and how to do a valve job. The service manual will probably be your best bet for further information.

 

[Gold Country Russ]

The actual valve job would be done by a qualified automotive machine shop with lots of experience and expensive equipment. It is usually fairly inexpensive and about $350. should do a typical 3.5-3.7 head including new seals & guides.
As for DIY labor to remove and replace the head a little experience, a manual, a good selection of metric tools, and a little patience should get the job done. In addition to a decent torque wrench the following specialty tools will also be required:
A. Compact damper puller. (Pulls damper w/o removing radiator or condenser. I bought an OTC puller from zoro.com)
B. Something to hold damper from rotating. (I used a big pipe wrench. Don't ask)
C. Damper installer. (I used metric all-thread, heavy duty nut, & heavy washer)
D. Torque angle tool. (The really cheap ones are junk & inaccurate. Frustrating!)
E. Metric male hex key socket set.
F. A good assortment of 1/4" socket extensions including some wobble. (Intake)
When I did mine it was one Saturday to pull head. Sunday I port matched the head & exhaust manifold, did the pre-cat delete, and cleaned a few parts. Also because they were easily accessible I installed a new alternator and starter. Monday morning the head went to the machine shop and the PCM & throttle body shipped by air to Supermodulation for some of his magic. During the week I picked up the head, collected more parts, & finished cleaning parts. Saturday reassembled the truck, it started instantly, and ran perfectly. In addition to the required gaskets, damper bolt, and head bolts I also replaced the timing set, hoses, belt tensioner, idler pulley, belt, plugs, plug boots, thermostat, alternator, and starter.
My manual (Haynes) said with my 2WD I needed to remove the steering gear to remove the pan. WRONG! Before removing the damper just unbolt the motor mounts & jack up the front of the engine under the damper to easily pull the pan.
Go for it.

 

[Timbubba]

$6000!! Sounds like way too much money for a new head to me too.

I'm still pissed at the GM rep because he told me to take it the dealership to see if it was the heads. To me that sounded like they would pay a good chunk of the repairs. After paying the dealership $400 to inspect the engine and confirm that it was the heads, all they offered was 5% off the cost of the repairs.

 

[Gold Country Russ]

The dealer should have given you two options to repair it. One quote using a GM reconditioned head and another quote for a normal valve job using new valve guides. The valve job quote should be $500-600 cheaper (and just as good).
If you decide to DIY PM me and I will give you some more tips.