I've been reading about the 3vze for a few months now and it seems like a very good engine except that heat will damage the head gasket because of the crossover pipe design. Since I can't really justify headers at this point nor can I weld up anything custom, I am looking for alternative solutions people may have come up with for limiting this head gasket issue. And if I wanted a 3.4 I think I would just buy a 3rd gen because that conversion is beyond me.

I have seen some people do a hood louver/vent and the drawback seems to be letting water in where it shouldn't be let in. Why not vent the hood, tastefully of course, near the crossover pipe (very back of the engine) and even possibly along where the exhaust manifolds are. There doesn't seem to be anything critical and electric back by the crossover.

Another idea is maybe putting some kind of fan inside the engine bay to get better circulation and possibly using this in conjunction with the vent.

What about pipe wrap or some other kind of heat deflection system to keep the heat away from where the gasket fails.

 

When I rebuilt mine last year I wrapped the crossover in header wrap.

 

I'd say installing headers will get the heat out of there faster and eliminate that engine killing cross-over that heat soaks firewall end.

Just my 2 cents!

Jim G.

 

The heat isn't the only factor here. The crossover pipe *can* burn out the rear #6 cylinder in some cases causing seals to fail but it's not very common. I don't recall ever seeing a head gasket failure along the rear of the engine where the crossover pipe is, it's always been in the center (near the #3 or #4 cylinders).

A big factor is the fact that the cylinder head and engine block are made of two different metals. They expand and contract at separate rates. It's a design flaw that cannot be corrected, as far as I know.

The best thing you can do is to monitor your coolant. Don't ever let it get low and don't ignore leaks. Replace every 30k miles per the FSM (unless you've got some pink long-life, but makes you wonder how long it will last?). Fresh coolant transfers heat better than old, broken down coolant. You could also de-grease your engine if you want but I've not had issues with that.

 

When my HG blew a little over a year ago the only spot that was burnt up was the corner of cylinder 6.

 

Yeah from what I have been reading it is commonly on 6, which is right near the driver exhaust mani and crossover joint. It blows elsewhere of course but #6 seems to be perhaps more frequent.

 

I notice there is a heat shield on the crossover and then again on the exhaust manifold (driver side) but no shield right at the corner of #6. Why not put some aluminum backed insluation pad on the engine with the aluminum facing the crossover/exhaust manifold intersection? Doing that plus a hood vent might drop the temp a few points.

 

Just did my head gasket. #6 for me as well.

 

LC Engineering sells their header crossover pipe a la carte for $200 if you email them. With that you'd only need to:
1) New flange on main exhaust
2) New flange on driver side downpipe
3) Block plate for drivers side crossover
4) Fab new down pipe for passenger side w/ flanges.

1-4 are all stuff an exhuast shop would be able to do for very reasonable.

IMO, the crossover delete should be at the top of the list after you take care of any safety and/or neglected engine maintenance issues like valve adjustments...

I'm planning to do above and install the LCE catback exhuast system at some point this year...

 

Is this something they could do with the components still on the car?

I read in another thread that a passenger side exhaust manifold can be used on the driver side and the benefit is that it doesn't have the crossover flange that the driver side does.

Also as an FYI to people with overheating issues over near the #6 and #5....if you look at the FSM there is a chapter called "coolant system description" I think. In there you can see the coolant flow and notice that the oil cooler goes right to the #5/6 cylinder. Mine was clogged and it seems fairly common for them to be clogged with what looks like sand from old coolant. I had to remove mine and blast it out with a pressure nozzle and garden hose. If the coolant isn't flowing through there unrestricted I could see it being an issue with not removing heat from the engine as well.

 

It adds add'l pipe cutting and fitting and heat shielding to use the passenger manifold on the drivers side. Not to mention the pain of removing and installing a separate manifold...

Conceptually, a passenger manifold should result in better exhaust flow, but it's playing in the margins and adds add'l and unnecessary costs. That's really the only gain -- having both passenger and driver side exhaust have more identical exhaust pulses... But if going through all the trouble for this, long tube headers is probably the better way to go...