So my stock R53 headers broke just before the cat. I had an R50 with a header just waiting to be used. Immediately after installing I noticed smoke coming from the header area... Smelt like burning oil, I figured there was just some residue burning off from me working in that area. I haven't noticed any smoke from there since then. But after the install I took it for a test drive and the temp gauge was all the way to the top by the time I got home. I reused the original header gasket as it seemed fine.

Coolant system isn't leaking, no air bubble, everything is good with that.

It's a very noticeable difference in the amount of heat in the engine bay. Everything is hot to the touch. It's winter here in SC so I've been running the heat on full blast to cool it off some. At one point the coolant temperature was up to almost 230 degrees.

Any ideas what could be going on?

Thanks NAM!

 

nothing would have changed coolant wise, unless you touched the reservoir when putting the header in. you may have bad adaptations from the bad header to the good one? but after a tank of fuel this should have changed. you can try doing the ecu reset and see if that helps. otherwise something in your cooling system happed to get compromised at that time. granted 230 deg coolant is not a big deal, getting over 230 you really should start worrying. at 230 the radiator fan will kick onto high

 

What is the condition of the R50 Cat? could it be clogged? Is your supercharger sounding louder than it did before you switched headers. I don't know if there is any difference in piping size between a R50 and a R53, it could be a restricted flow problem. I know when my cat clogged, anytime I went up hill my temp would increase very quickly, and my sc sounded like it was working overtime.

No idea if this is your issue, just a thought.

Nik

 

If the cat was plugged, the car would most likely not start. There is an old trick of putting a potato in the exhaust pipe to keep somebody from starting their car. The engine compression is not enough to force the potato out. If the cat was partially compromised then I am wondering if the O2 sensors would alarm.

Could it be mere coincidence that the thermostat went and the oil was just that, oil that burnt off?

 

Fair enough. "Restricted" then. From personal experience, if the exhaust flow is "restricted" it will overheat.

 

Where was the R50 manifold stored, in other words could a mouse have built a nest? The heat would burn allot off but if it was between the engine and the cat the residue could be the restriction.

 

Pull it off and hollow it out then it's off the table if it does it again

 

Did you forget to reinstall the heat shield underneath coolant expansion tank? Maybe header is heating that up?

I'm sure it wouldn't make that big of a difference but still, something to check!

Also if your header broke at that joint, it's incredibly likely you have a bad motor mount.

 

I'm in the process of finding a good mount. Probably LEM Forder(SP?)?

Yes, everything was defiantly put back the way I took it off. The R50s header was on the car still installed. I never had a problem with it on the R50, either way I'll be buying a new one. Probably OBX and wrap it?

Also, does anyone know the normal manifold pressure while running at highway speeds?

By the way, I did reused the old gasket? Could that be a problem? Seems like too much exhaust heat in the engine area.

As far as the tstat goes, what would be symptoms of that being bad? Coolant system seems to be doing its job, just having to work overtime in stand still traffic due to the heat.

Good thing it's winter down here so I can blast the heat!

Thanks for all suggestions guys!!

 

Being a transplant to below the mason-dixon line, I always chuckle when discussions on winter come up. I grew up with snow banks touching the telephone wires on the pole and 35 below (real temp not windchill). I tell the locals that if the civil war was fought today the south might win as long as they don't fight in the winter. 2" of snow and schools close for a week.

On the tstat, they can either be both stuck closed or partially stuck. If partial, the water does not circulate properly and you overheat.

If you knew somebody in air conditioning they could test the CFM on the tail pipe with a simple gauge that looks a little like a tire gauge. You could compare to another car that does not overheat.

 

I have several friends in the AC business actually. One I converted over to a Miniac, he now owns 2 and loves them! I'll check with him on your suggestion!

Btw, I agree with the winter thing. But today the high is 32, we have snow "flurry's"! Annnd of course every grocery store is sold out of bread, milk, and eggs.

"Snow and ice" in the south is such a laughable situation.

 

The older ac guys will know about the pocket duct flow tester, very similar to a tire pressure gauge but is L shaped with a head that points toward the register. The younger guys will know the digital tester that has a small fan type blade that spins around.

 

Yea, the mounts definitely need to be replaced. Which position mounts are you thinking would be the most effective to start with. The R53 has 3 upper motor mounts and only 1 lower, correct?

There is a great deal of vibration in the cabin, progressively getting worse over the past couple of months, so the mounts have been on my to-do list for a while now, along with some other front suspension components.

​​​​​​​
This is definitely on the table and will get my friend to check it this week, provided he is able to come by the warehouse. He'll probably know about both as he's been doing HVAC/Commercial Kitchen Equipment/Gas repair almost his whole life.
Great suggestions guys!

Big thanks as always guys!

 

Are you sure the Fan Motor is coming on?

Double check, your ELECTRIC Fan. I'm pretty sure it should be controlled by a resistor pack so that it has a LOW and HIGH speed.

Motor on!

 

The upper passenger side mount is usually the one that goes bad. My first mount went bad and leaked all over the frame rail at 17K miles. For the smoothest ride, the OEM mount is the best, but be prepared to change it in the future as they don't last as long. One of the best mounts, but expensive and with a little more vibration, is the Vibra-Technics mount.

Something cheaper is/was the TSW urethane mount. not sure if it's still available since they might have replaced it with a V-T styled clone for $300. It used to be about $150.

 

Yup, it's definitely coming on. After sitting in traffic for about 1 and ½ hours it was still running when I got out the car. Don't believe that's the issue... Still stumped.

Also, when I turn the heat on sometimes I can smell the sweet smell of antifreeze?

 

The smell is the heater core leaking into the duct work , probably not why your overheating but another issue .