3500 LX9 seal improvements

[rel1939]

Hi

I am thinking of trading my Olds with the 3800 for a Malibu / G6 with the 3500.

I have heard that GM has improved sealing on the lims.

In fact some have said that coolant is now routed outside via pipes rather than through the intake. Is this so?

[SappySE107]

If its an 07 3500 with VVT, then yes. Otherwise its the same as the 3400 as far as the coolant routing goes.

[rel1939]

Hi

I was looking at a press release photo of the 3500 LX9 and it appeared to have a pipe running around from left to right before entering the plenum



what is that pipe for..i wouldnt think it was pcv?

[SappySE107]

Its to the heater core. They have had that since the FWD 2.8 at least.

[rel1939]

Hi

You meant that pipe out front , that crosses under the dipstick?

[SappySE107]

That is correct.

[MMGT1]

I just noticed where the O2 is! That is going to make things tricky for tuning....
Only going to be able to read one bank instead of two, unless you weld in a bung.

[SappySE107]

2 O2 sensors.

[IsaacHayes]

MMGT1: it may have 2 O2s?? I would think so since it has dual exhaust that goes to a Y pipe under car.

[MMGT1]

That would be nice if it did too. Then you could go from one bank to the other, never been able to do that with a V6. That is what is nice about the 8's, can tune both banks, one at a time. In the 3400 now, having it in the rear at least, it reads both banks...

OK who on here has one of these?? Post a pick of the back of the motor if you can

[rel1939]

Hi

So, have these LX9s been free of the intake leaks of the previous 34 and 3100s?

[IsaacHayes]

The LX9 has a plastic intake gasket like the 3100 & 3400. Looks like the same setup, but Felpro doesn't make the metal gaskets for these motors yet. I would think they would have the same problems eventually...

[Superdave]

If you use dex cool it may have the problem down the road.. I'm using the green stuff in mine so i doubt i'll see anything.

and yes it has 2 heated o2 sensors, you can see them both in this pic.. http://www.3500z.com/3500/mini-3500%20008.jpg


that's IF you have the version from a Malibu with the exhaust routed under the engine, some have the same manifolds as the 3400 so there is only 1 sensor.

[IsaacHayes]

dexcool or not, my car has never had dexcool and has the plastic style gaskets and has failed twice! Unless the lx9 uses some different plastic that doesn't get brittle or warp (both problems) then I'd assume that it could fail at some point too.

[rel1939]

Hi

.. I'm using the green stuff in mine so i doubt I'll see anything.

The problem with the color of coolant now, is that it doesn't necessarily mean what it used to.

In the past, the green was silicated , conventional coolant. Such is almost always now, not the case. The "green" universal is usually just a OAT coolant just as Dex is.

You can check the ingredients of each and chances are, you find the tell tale additive 2-EHA . The color is just a dye added by the manufacturer.

In my Olds (3800) , I used the Fel Pro lowers 2 yrs ago and 100,000 miles and flushed the Dex out for G-05, which is a Hybrid OAT. It has some silicates but tolerates air much better.

Last used oil analysis showed no leakage.

I am going to email FelPro to see if they intend on making a Problem Solver gasket for the 3500 just as they have for the 3400s.