MAC Headers and oil consumption

Skud · Apr 24, 2006

Hi All,

I bought a set of the Ceramic coated MAC headers. Shortly after I started to read some threads about people installing these headers and their oil consumption going way up.

I decided to send an email to MAC's technical support to see what information I could find.

This is my original email to MAC sent on April 22, 2006.

Hello,

I've recently purchased a set of Ceramic coated long tube headers for my 2002 Mustang GT.

Shortly after purchasing them I began reading many reports of people having severe oil consumption (1 quart per 100 miles seems to be the reported average), severe blue smoke out of the tailpipe and engine damage. The reports claim that only the MAC long tube headers were installed and the smoking occurred almost immediately after installation.

Upon disassembly of the engine, many people have reported finding a fine "sand-like"substance in the oil as well as scoring in the cylinder walls. The result is, of course a ruined engine.

As I continued reading I had only become increasingly concerned that these weren't a "few crazy people who don't know what they are doing". These are people who know a thing or two regarding automobiles. Some of the individuals have had the headers professionally installed by speed shops and some have done the installation themselves. The results have been the same either way. Blue smoke and engine damage.

I am wondering, what can you tell me about this situation? Is MAC aware of this issue and has it been corrected? With the number of incidents occurring I am debating on whether or not to return the headers for another brand. I would rather not, as the MAC's I have now look to be high-quality pieces.

If I receive no response to this email I will assume that you have no guidance for me and I will be returning the MAC headers for another brand. This is my first MAC product I have bought and I would hate for it to be my last.

I await your response.

Thanks!!
Riley Foster

I received this responce today (April 24th, 2006)

They smoke because there is no back pressure, most likely these guys are running off rd pipes. Its not the headers but the stock heads. They cannot handle the extra velocity and seep oil. The headers are actually doing there job very well, the high amount of velocity in the exhaust “quicker rev time” creates a ventura or a suction the oil seeps through the stock valves. I have a ls1 camaro 2001 I put the headers and off rd pipe on and I got blow by “too much velocity in the exhaust” and smoke came out my tail pipes. Vehicles are more prone with the air intake and off rd h pipes, I put my cats back on problem solved. This only occurred at 4500-6000 rpms wide open throttle. ITS NOT A HEADER ISSUE IT’S A FORD ISSUE. Ford designed the stock valves for the stock exhaust you run headers and off rd and you get smoke or oil consumption.

Thoughts??

Thanks!!
Riley

BurningRubber · Apr 24, 2006

1 quart per 100 miles?

DAMN! I dont see why "backpressure", or a lack of is going to increase oil consumption like that, that much so.

So supossidly that letter is saying anyone with longtubes, and an o/r midpipe is gonna consume oil? Hmm...

mogs01gt · Apr 24, 2006

It happens on the 4v engines. Its a scavenging issue, not back pressure. I never had that problem. with my MACs.

Skud · Apr 24, 2006

I'm wondering what they have to say about the "sand-like" substance and scored cylinder walls..

He didn't seem to comment on that. I'm assuming it was a he as there was no name on the email...

Riley

sgarlic · Apr 24, 2006

The guy knows what he's trying to say, but just said it rather poorly. I've read several other threads relating to the increased scavenging resulting in oil consumption.

I haven't heard of a quart per 100 miles, perhaps whoever had also had very high mileage or leaky valve seals or some other issues or something.

I believe that sand thing/scorred cylinders was from places where mac didn't properly remove burrs from around the rim of the ports, and in the "ventura" or whatever the mac guy called it, pieces get sucked back up in to the combustion chamber somehow. In just about every Mac header thread I've read, at least one person usually mentions to go over them very well with a dremel wire wheel or a wire brush before you install them.

mogs01gt · Apr 24, 2006

sgarlic said:

I believe that sand thing/scorred cylinders was from places where mac didn't properly remove burrs from around the rim of the ports, and in the "ventura" or whatever the mac guy called it, pieces get sucked back up in to the combustion chamber somehow. In just about every Mac header thread I've read, at least one person usually mentions to go over them very well with a dremel wire wheel or a wire brush before you install them.

Any aftermarkpart should be looked over with a fine tooth comb. I have never installed any part on my car without inspecting it first. I cleaned my MACs up and they turned out great.

If you install something on your car without checking to make sure its 110%, its your fault.

COBRA90GT · Apr 26, 2006

AFAIK, it is (was) mainly a problem for the 4V engines. People were pointing the blame at MAC's quality control process for leaving excess welding slag inside the headers and the great debate about "too much vacuum" ensued.

The following thread covers that story (in great detail):

http://www.corral.net/forums/showthread.php?t=167953

Bottom line, make sure your headers are clean prior to installing and be wary of MAC longtubes on a 4V engine...

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MAC Headers and oil consumption

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