I need 3 rows of seats and more towing power....

[anw7405]

I'm just looking for ideas at this point. I had a 2000 suburban with 3.73 gears and the 5.3 and it was not enough to pull my travel trailer good. I broke down and got a 2007 6.2 denali with a 3.42 rear end because everyone said it was a great tow vehicle. We just got back from our first trip in the ozark mountains and I was less than impressed with it. I want to be able to go out west and not worry about my tow vehicle. Long story short the tranny and engine ran pretty hot and made knocking noises at random times. I will keep this for now probably with an additional tranny cooler but what do I need to look for. Old 8.1 burb? 2008 and above with the 6.0 2500 burb. diesel excursion? anybody have any experience with these? I bought a light travel trailer for this specific reason at 4,650 lbs...probably around 6,000 with all weight added.

[anw7405]

PAThwacker wrote:
5.3 half ton burbs are meant for daycare.

??? Is this just a general statement or did someone mention a 5.3 suburban somewhere?

[PAThwacker]

5.3 half ton burbs are meant for daycare.

[Turtle_n_Peeps]

They're cast in Ben.

The block material has nothing to do if they are repairable or not. Labor in the field will eat up the cost of a factory built engine and then some. It's cheaper for them to just get an engine and slam it in and be done with it.

[BenK]

Hope your warranty covers it and be careful answering verbal and/or written statements.
Especially in regards to towing. Key it to be under the OEM ratings/limits/etc
or just be ignorant of them

Anyone know if this aluminum small block 6.2L has cast in or pressed in cast iron
sleeves?

Assume either cast or pressed in are not wet...right?

Pre-ignition and/or knock can destroy an engine quickly and the larger the displacement,
the higher the chance of damage

Shouldn't be fragments...that would mean something different to me...or it has
gone beyond just melting/busting holes/etc from knock/pre-ignition...

Please post back the results, am very interested

[KKWilliams]

Sorry to hear that. I'm hoping your warranty company covered it.

[anw7405]

Well after a bunch of run around with the warranty company and the dealership we are pretty sure the engine is toast. I will probably find out more Monday after they remove valve covers and drain oil to look for any fragments of metal. If they find any at all they are replacing the entire engine since it is an irreparable aluminum block.

[BenK]

anw7405 wrote:
Good news and bad news:

Good: The transmission cooler worked great. Highest temp of the trip was 190 but normally stayed in the 170's.

Yes, good news and telling that the OEM aux cooler wasn't sized large
enough. Either for the load or the higher heat generated by the 'condition'
of the tranny.

'Condition' might be that it is worn/wearing out/etc so not as efficient
therefore generating more heat...or the load is over it's ratings of
that 'condition' of the tranny

Bad: Only made it about 20 miles before the engine light came on and the noise started.

So you have eliminated the tranny's contribution to the overall heating
of the main radiator...

So it can be that the engine isn't able to manage that level of load,
previous knocking sessions caused the engine to weaken (could be pistons/valves/etc
to burn (melt), to something in the CC

As said, knock can ruin an engine real fast if left in that knocking
condition

Am assuming highest octane you can get, that there isn't any mod's
to the engine (tune, etc).

And back to what Turtle said earlier...check your cooling system and
especially the 'stack' (AC radiator, ATF Aux radiator, main radiator).

Also, OATs coolant and the issue(s) with oxygen getting in there to
turn DeathCool into acidic, gelatinous globualls that will plug up
the radiator(s)

Truck is at the GM dealership now. Hopefully they can figure it out.

To the denali owners. What oil pressure are you running while towing 2500-3000 rpm's? I'm only running about 25. I don't feel like that is enough. Thats my only explanation for the noise and oil temp. I know the oil is hot because that is the first thing I check when it starts making noise. It smokes a little out of the dip stick hole when i check it.

[95jersey]

Have you thought about an aftermarket intake and exhaust? Not related, but I put both on my Ram 5.7 Hemi and it made an amazing difference to an already powerful engine.

[anw7405]

mkirsch wrote:
You can't blame towing on your engine problems. You haven't used it enough to cause any major harm yet!

Basically, you bought someone else's problem. The previous owner knew something was wrong with it and dumped it like a hot potato.

I agree. But you can't tell anything is wrong with it until you drive it hard or put it under a load for an extended period of time.

[HaulinBass02]

Get it fixed and find a 2500 Suburban. I tow our TT in the signature with ours and with a few small mods it tows great. I don't know what our trailer weighs but I have 7 people (granted some are halflings) and my Suburban rides on 33" tires with 3.73 gearing. It still tows very well. I lock out 6th in tow/haul and let 'er go.

So yes, there obviously is an issue with the engine in your Denali. If it was spark knocking the ECM should have pulled timing. Sounds like it was an oil pressure issue which is infinitely worse and more likely rod knock you were hearing or even a clogged oil passage causing bad lifter knocking. Do you know what the code was?

IMHO, the 2500 is just a more comfortable tow vehicle. It handles the heavier loads better, the engine is built for towing and the 6L90E is stronger. The platform is built and tuned for towing. My wife daily drives ours. We had an '07 Suburban 1500 with 5.3L in the past and she prefers the 2500. They aren't impossible to find but they are worth their weight in gold, i.e. they hold their value very well.

[mkirsch]

You can't blame towing on your engine problems. You haven't used it enough to cause any major harm yet!

Basically, you bought someone else's problem. The previous owner knew something was wrong with it and dumped it like a hot potato.

[anw7405]

I took it to the dealship today. They said there is for sure something wrong with the engine. In short they are going to start tearing it apart and see what they find. Shop foreman came out and talked to me for about 30 min. We will see what happens from here.

[KKWilliams]

anw7405 wrote:
All good ideas. The duramax vans only come in the cargo I think. Maybe the new ones come in passenger but way too much $$$$.

See my signature line, I have a 2012 duramax passenger van. You can find used ones below 20k now. It will take some looking and you may have to drive to another state to get one. On the 4x4 you would have to look at aftermarket conversion.

BTW, sorry to hear about your mechanical issues. Hopefully they quickly find a reason why your oil is running hot.

[anw7405]

Good news and bad news:

Good: The transmission cooler worked great. Highest temp of the trip was 190 but normally stayed in the 170's.

Bad: Only made it about 20 miles before the engine light came on and the noise started.

Truck is at the GM dealership now. Hopefully they can figure it out.

To the denali owners. What oil pressure are you running while towing 2500-3000 rpm's? I'm only running about 25. I don't feel like that is enough. Thats my only explanation for the noise and oil temp. I know the oil is hot because that is the first thing I check when it starts making noise. It smokes a little out of the dip stick hole when i check it.

[Eng208]

I think you have enough vehicle for the trailer you currently have. Shouldn't be a problem. However, the spark knock you are experiencing is a problem. That engine is designed to run on premium to make the performance advertised. That allows the computer to adjust the timing depending on the load as much as possible. The engine has a piezzo spark knock sensor that senses the knock and adjust the timing to eliminate it. Without the higher octane fuel, it can't get rid of the detonation. So power and engine longevity suffers. The other issue could be the sensor detecting the load on the engine. GM used a manifold Absolute Pressure sensor in the past located in an area that carbon could plug the hole. This prevented the computer from reading the loads correctly and would lead to spark knock on hills without affecting other driveability. Went to three dealerships before learning GMs system and fixing it myself.