My front oil cooler setup -- why's it failing?, Installed May 2007 Options

[GTeener]

May this be a lesson to us all (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/headbang.gif)

Driving from Fair Oaks/Sacramento to Vacaville last Sunday. Filled the tank up before leaving town (1/2 tank of Premium gas). During freeway drive, started noticing and getting concerned by the rising oil temp and falling oil pressure. Peaked at 260+ oil temp and the 30 psi oil pressure reading on the gauges.

The engine made a sputter crackle sound like it was running rich at one point in slow traffic at the Hwy 50 & Hwy 80 merge. There was a puff of dark smoke upon acceleration. The engine didn't stop sputtering and there's been a knocking sound ever since, but there's no dark smoke. Lost my go power too. Feels like it isn't in the proper gear or something. Possibly missing a cylinder??

I stopped for lunch in Davis to let the engine cool off and stretch the dog. Drove some more without any noticeable improvement in the temp or power situation. Stopped at a 76 station in Vacaville to look more closely.

There is oil in the tank and it looks clean, but the level is above the fill dot.
No distributor wires are loose. Engine bay looks clean...No obvious oil leaks/spray. Got flatbed towed the rest of the way home by AAA.

Best I can tell, the oil may not be circulating properly. Best guess is that the thermostat isn't opening or there is a block in the oil cooler line somewhere but don't know why.

Leamon Stansell (HealToe914) did the oil cooler setup work in May 2007 (pictures below).

The car hadn't been driven much since. Half the tank of gas was 7 mos old (Premium) when I hit the freeway on Sunday.

Waiting for Rich Walton at Jerry Woods Enterprises to give me the go ahead to have the car towed to them for further diagnosis and repair but thought it *might* be worth getting *the group's* opinions/experiences on the subject.

[SLITS]

Gwen, it looks like a MOCAL thermostat in the third picture. That needs to be checked to see if it is functioning. If not, the front cooler is inoperable. It works the same as the on-engine thermostat directing oil to the cooler.

[Root_Werks]

I'm starting to think a failed(ing) oil pump.

Oil cooler lines are long and require a lot of pressure and volume from the pump.

Low flow = higher temps and really low pressures when the thermostat is open.

If the engine was a dead cold, I bet you'd have higher oil pressure for a while until the thermostat opened.

It's a thought. (IMG:style_emoticons/default/confused24.gif)

[SLITS]

Long lines don't create that great of restriction, but the number of 90 degree fittings certainly do.

[GTeener]

Gwen, it looks like a MOCAL thermostat in the third picture. That needs to be checked to see if it is functioning. If not, the front cooler is inoperable. It works the same as the on-engine thermostat directing oil to the cooler.

Does a MOCAL thermostat have a history of suddenly not functioning?

[pcar916]

Bummer (IMG:style_emoticons/default/dry.gif) Hope it's easy and cheap.

In lot's of healthy cars the thermostat doesn't open very often, but in your part of the country I should think they would. But those temps are certainly too high. I'd check the auxilliary oil system for sure but the motor will have to be thoroughly inspected now. The Woods and Walton will certainly do that. I see two things off the bat.

As long as nothing is wrong with your pump or internal oil cooler... assuming you have one;

1. As stated above, the Mocal thermostat should be checked per their instructions.
- Did you check the hose temps to check that flow was happening?
- Does the front cooler get hot?
- You can check the temp at the inlet and the outlet (infrared) and find out how many BTU's the cooler is pulling from the oil.

2. the holes under the front bumper were never enough for my motor. But I don't have a cooler behind cylinder number 6 either (993). Your motor does yes?

3. Where does the exhaust for your front cooler exit the car?

I have relocated the thermostat into the front trunk so I can get to it quickly. Getting wrenches on the AN fittings while the motor is in the car was exasperating when mounted on that firewall. I've never had a problem with it and I run 18 qts of synthetic oil.

FYI: I've run my Mocal thermostat for the last 11 years with no problems.

Good Luck, and let us know what happens!

[pcar916]

... Also, you have the oil inlet (on the front cooler) on the bottom fitting right?

If it's on the top, the oil never fills the cooler and get's completely cooled. It just dumps from the top to the bottom in the first few tubes. And oil in the front circuit is very foamy, it needs to inlet on the bottom!

Also those 90 degree fittings appear to be mandrel-bent. Those are ok if you don't use too many. Normal 90's are... lacking in goodness.

[Eric_Shea]

I have a new MoCal if that's what's needed. Not going to use it.

[Dr Evil]

pcar, I have heard that putting your thermostat in the front is a bad idea as it makes your engine push around too much cold oil. True?

Knocking is seldom an easy thing. I hope all goes well. Does it sound like a rod knock? Spun bearing?

[pcar916]

pcar, I have heard that putting your thermostat in the front is a bad idea as it makes your engine push around too much cold oil. True?

I've heard the same thing at times and was concerned about it too since we don't have that onboard cooler. But I know a lot of racers that run them in the front trunk as well. When I converted the car from a 2.7L motor (1999) I was very active on the Rennlist/Porschelist forum and we bantered about pros and cons for several weeks on this topic.

I elected to go for the empirical crowd's opinions and plumb it that way. But I use all mandrel bent fittings (45 degree's when I can) aeroquip hoses and only synthetic oil. That said...

I've checked to see how early the oil goes through hot and since the hoses are exposed in the passenger compartment (through the heater tubes in the longitudinal) by the passenger's right foot. I can tell when they get hot with a passenger willing to touch them, or with my narrow-beam infrared thermometer, which tells me when things heat up. To your question specifically, I was curious too.

So I watched the temp gauge to see when I hit 180 and felt the hose to the cooler to measure how quickly it released the hot oil forward and it happened, for all practical purposes, at the same time. I'm good!

[GTeener]

pcar, I have heard that putting your thermostat in the front is a bad idea as it makes your engine push around too much cold oil. True?

Knocking is seldom an easy thing. I hope all goes well. Does it sound like a rod knock? Spun bearing?

Not sure I know what "rod knock" or a "spun bearing" sounds like. The guy at the gas station behind me actually said "it sounds like rod knock" when he saw my head in the engine bay, but I didn't know what he was talking about (IMG:style_emoticons/default/huh.gif)

[ConeDodger]

What would a pulled head stud do?

[siverson]

I think this is easy... You need much more air intake (bigger hole in the front bumper) plus you need a shroud to exhaust the air. Where are the hole(s) in your front trunk for the exhaust air?

I'm not surprised what you pictured doesn't work. My oil temps were much better on track days once I spent more time carefully routing and sealing (pushing all the air through the cooler) my front oil cooler shroud.

-Steve

[GTeener]

I think this is easy... You need much more air intake (bigger hole in the front bumper) plus you need a shroud to exhaust the air. Where are the hole(s) in your front trunk for the exhaust air?

I'm not surprised what you pictured doesn't work. My oil temps were much better on track days once I spent more time carefully routing and sealing (pushing all the air through the cooler) my front oil cooler shroud.

-Steve

There are exit holes into the wheel wells. The front trunk has one of those felt covered Masonite (or whatever it is) "floor boards" over it. The shelf board that covers the spare tire....you know...

[IronHillRestorations]

I'd respectfully disagree with Steve.

Just running the oil up to and through the cooler should be enough to controil oil temps of a street car with a 2.2S engine, unless it's way too lean and the timing is too far advanced.

You may want to have the oil lines pulled and checked for a restriction.

I've used a few hundred feet of stainless braid oil line without any problem, bullet proof stuff right? Well no, I had a situation where the oil line internally collapsed, and there was no outward signs of any problem. I called BAT (the Mocal people, and where I get some of the AN hose and fittings) and they said "well I guess you've finally got enough hose to see that, it's rare but it does happen".

[SLITS]

My assumption was that the cooler was installed prior to her trading the 6 for the Mini and that it had been driven with success ... oil temps & such. Now that she has it back, the problems are occuring.

Rod knock ssounds like someone tapping metal with a hammer. Noise increases with RPM. Offending rod can be found by disconnecting sparkplug wire and noise will cease with the offending cylinder/rod.

Pulled stud will be heard on acceleration if the head is actually loose. Sort of a popping sound on acceleration. 1 pulled stud does not usually make the sound. Pull valve covers and look for loose barrel nuts in the rocker boxes.

Oil pressure will fall if the oil gets overheated .. 260 is way high.

The Mocal can fail as the one on the engine. It is just a wax thermostat I believe.

If the transfer lines were copper, brass, aluminum or steel, there would be some heat transfer to the air stream. The lines appear to be hose, so the heat transfer to atmosphere would be minimal, if any.

Anyway, this probably doesn't answer what is wrong but a sudden missfire brought on by high temps is not the best sign in the world. Good Luck.

[rwilner]

I run 18 qts of synthetic oil.

Holy Crap!!!

[GTeener]

My assumption was that the cooler was installed prior to her trading the 6 for the Mini and that it had been driven with success ... oil temps & such. Now that she has it back, the problems are occuring.

True, install happened before the Mini trade. Car drove fine. After the trade back and subsequent heat problems I asked about the temps and oil and was told the oil was checked but never changed. The car wasn't driven much. Around the neighborhood mostly. The oil temp was running 260 ish but was assumed normal for hot valley weather & air cooled engine.

[76-914]

Long lines don't create that great of restriction, but the number of 90 degree fittings certainly do.

(IMG:style_emoticons/default/agree.gif) One non-radiused 90 ell = 6' piping on 3/4" ID tubing. That's for water anyway. Maybe less for oil 'cause it's slicker! (IMG:style_emoticons/default/slap.gif) (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/lol-2.gif)

[DanT]

My assumption was that the cooler was installed prior to her trading the 6 for the Mini and that it had been driven with success ... oil temps & such. Now that she has it back, the problems are occuring.

True, install happened before the Mini trade. Car drove fine. After the trade back and subsequent heat problems I asked about the temps and oil and was told the oil was checked but never changed. The car wasn't driven much. Around the neighborhood mostly. The oil temp was running 260 ish but was assumed normal for hot valley weather & air cooled engine.

(IMG:style_emoticons/default/pinch.gif) (IMG:style_emoticons/default/pinch.gif) ouch! that can't be good...