how feasible is this simulation

[Shun]

By way of multiple different posts here in the zetec forums, I have come to the conclusion that I need to replace my valve cover gasket and will be replacing it next week along with a couple other things. I had been trying to trouble shoot some sort of over heating, and was completely baffled that my CHT sensor wasn't picking up anything abnormal, Then I got to thinking and am wondering if this simulation is possible.

Valve cover gasket cracks.. driving car at highway speeds.. approximately 3,200 rpm. heat escapes engine block by way of the cracked valve cover gasket(would that even happen?) the heat causes the engine coolant bypass tube to crack, giving the impression that the engine coolant is either too hot or too pressurized

I had been trying to figure out why my CHT sensor hasn't picked up anything abnormal and why my cooling fans weren't coming on, but perhaps the coolant isn't above the controlled range so the fans aren't supposed to come on, and the engine isn't over heating, but rather heat is escaping. this may be a no-brainer, but I am still learning and unsure if the cracked gasket would allow heat to escape

[Liquid_02_ZX3]

First off your engine bay gets insanely hot. A seaping valvecover gasket does not put out anymore heat than a non leaking one. Your CHT and cooling system see's temperatures above 200 degress everytime you drive your car. Its all engineered to take the heat.

So that scenario is something that would never happen.

[Shun]

so then the bypass tube having cracked was either from too much heat, or the cooling system being to pressurized?

[G-forces]

How old is the coolant tube, maybe it's just worn out. Do you have a header? If so, is it wrapped? When you drive, do you like to keep it above 4K rpms for extended periods (in lower grears)? Do you run a stock tune, or something else?

[Shun]

the tube could've been warn out. I purchased my car used last october(2007) so I am unsure of the maintanence and am preparing to do a major tune up and clutch system replacement over the course of the next month(using money from my next two-three paychecks) but am gathering info on a few other problems that are outside of the major tune up list in my haynes manual don't have headers, the car is fully stock for right now except for the rear exhaust resonator and "lunch box" muffler removed, with piping and an Apexi N1 muffler tip in their place, which was on the car when I got it. and no, the only time I ever go over 4000 rpm's is accelerating onto the freeway, and only in first gear- other than that I cruise at about 3,200 rpm at 65 mph in 5th gear - don't like staying up in the rpm range right now, until I get a compression check for some sort of idea of the internal condition of the engine as it's at approx. 95K miles. the tune is completely stock, as far as I know anyway, seeing as I do know that the owner before me was a froofroo woman I doubt she had any sort of tune.

[G-forces]

Humm, too bad (at least for easy answers) that none of those things is going on. How about the sound in the engine bay with the hood up. Is it loud, or raspy in there? Just wondering about exhaust gas leaks under hood...

How about power? Does the car seem to start off good then run out of power mid way up the rpm range?

[Shun]

There aren't any exhaust leaks, that neither myself nor my neighbor were able to detect. here is what I know is wrong with the car.

Engine:
bad valve cover gasket
spark plugs wearing out
bad pcv valve
bad DPFE sensor
bad Idle Air Control Valve
timing belt tensioners failing(timing hasn't been effected too much yet)
rear engine mount

Drive train:
about 35% left on clutch
pressure plate wearing down
bad throw-out bearing

Additionally I was thinking the cooling fan relay to the resistor pack needs to be re-wired but as of recent I am not really convinced that my fans are malfunctioning other wise the CHT sensor should've picked something up and shown the engine over heating via the crappy stock cluster gauge. to validate this, I will add that I have replaced the resistor pack and the CHT sensor. Also, I can engage the fans via the relay in the A/C system. Needless to say, with the much needed major tune up, my engine doesn't sound too happy. I'm not sure, but don't think that one of the many things I need to do to my engine would cause the amount of heat to come off of it.. then again It could just be me being paranoid, especially after my bypass tube cracked.. which happend after I initially was concerned by the "abnormal" under hood temperatures

[G-forces]

Then how does your oil look? Are you seeing rapid darkening or any odd smells? Just as a precaution, you might want to hook up an oil temperature and pressure guage for a nice long run, in various driving environments, just to watch the internal temps, and see if those temps in will be ageing your oil at a faster rate than normal. I don't see that as a cause, but a potential negative effect. However, poor lubrication will increase running temp.

[Shun]

I've been keeping and eye on the color and texture of my oil, it seems fine. I've been using motorcraft 5w20 synthetic oil, but seeing as my engine is approaching 95K, I am considering to switch over to valvoline 5w30 fully synthetic high milage. I was already planing on hooking up some water and oil temp gauges, so I can also hook up an oil pressure gauge too. you know, come to think of it, would the engine run above normal temperature if there is TOO much oil in it? I remember I accidentally put 1/2 quart too much oil. the crank case was over filled and some oil went up through the engine breather and into the air box, not much. so I drained some of the oil, but it's still a bit more over filled. should I try draining a little more to try to get it to an even 4.5 quarts?

[G-forces]

I don't think it's the cause of the high underhood temps, but poor lubrication will add to it. I would expect the ECM monitoring of running temps would show a code or keep the high-speed fan going allot if the engine was running way too hot... since you have checked or replaced the control units for these, they should be operating correctly. That said, you already know you have to fix a bunch of little stuff that is making it run less efficiently, and doing those things will probably help.

A short period of time with poor lubrication will not cripple an engine, but will remove a little service life. Oil foaming is BAD! Too much oil in the crank lets it get whipped into a froath by the crank, oil pressure will drop dramatically if the pump picks up foam instead of liquid. Oil has additives to reduce foaming because it happens a little anyway, but they can't handle an overfull condition, where the crank acts like a Quisinart. You should drop it to 4.5 quarts, even though there is certainly a little "fudge factor" built-in to that requirement.

[MichaelXi]

Where EXACTLY was your break?

I had a Junction in one of my heater hoses... TWICE... For No Apparent reason.
It's been awhile now, but both breaks were identical, spilling All of the coolant, and Seriously Stressing my engine as I limped to water.

[Shun]

The break was in the plastic bypass assembly tube which is located towards the front of the car, under some hoses. here is a picture for reference. note, this is NOT my engine bay nor my car, just a pic that I found as I do not have a camera and my cell phone doesn't take that great of pictures.

[MichaelXi]

Ah. My break was a plastic junction directly below the coil. It Sheared Completely. TWICE.

[Shun]

Okay so I drained that extra 1/2 quart of oil out of my engine. it was MUCH more aged than the last time I checked it which was about 2-3 weeks/ 400-600 miles ago. it looks about ready to be changed soon. perhaps too much oil was leading to poor lubrication which was leading to high internal temps that just didn't reach the cylinder head?

[G-forces]

Yep, if oil gets foamy it will oxydize faster (burn up a bit), and your engine will run hotter, but that extra temp should reach the cylinder head just as much as everywhere else on the motor. That's the mystery part... try changing out the stuff you know is bad and see what happens now that the oil is right.

[Dads03SVT]

Could do what a friend of mine did...when he changed his oil he deleted one quart for a quart of Marvel Mystery Oil...ran it for a 1000 miles and then changed oil & filter.....heard that cleans a engine out also heard of people doing the same with a quart of transmisson fluid..??

[Shun]

There is actually one more "symptom" that my car has, which I have forgotten to mention. after my drive home from work(it's warmer this time of the day) my engine will be hot as previously stated, heat raises off of it. also there is a crackling noise from my engine. what could that crackling noise be?