Plain Jane OEM nothing to see here rebuild

JustJeff · 05-27-2012, 07:58 AM

I'm having overheating issues with the engine. I'm using a Taurus efan and Starion thermoswitch in factory location on the back of the water pump housing. Starion switch IIRC is a 195 on and 185 off. I also have a manual on switch wired to cockpit of the car. Fan seems to be working perfectly. I have it wired directly into the main fuselink in the engine compartment on the low setting. I have it setup so that I can swap between to high setting by simply unplugging the low spade terminal and plugging in the high.

Here is what I've noticed so far with normal driving (not driving it hard as I'm still breaking in the engine). Temps will keeping rising and rising and when they start to pass 220 I'll pull the car over and either let it idle with the efan running and hood up or turn off the engine but let the efan run and every so often turn the engine on to cycle what is in the radiator back into the engine.

Here are the contributing factors I've tried to narrow down so far:

Put in a new thermostat and while doing that changed to a different used, but working water pump. (It was working fine last time I used it, can mechanical pumps fail?)
N/A hood was being used. While I've been driving to avoid boost as much as possible. The Hallman MBC is set to zero boost, but I need to watch how I'm driving. The OEM wastegate simply can't fully bypass. I thought that perhaps because the MBC was not allowing the engine to be in vacuum that it was contributing to heat. By that I mean it may be purging as much of the pressure as it can, it's also trying to keep pressure at zero. That perhaps rather than having vacuum having zero pressure is still pressurized compared to vacuum and thus creates heat. That theory was partially blown out of the water, I put a turbo hood on it yesterday hoping to see lower temps...and did not. (Before it is said, I'm using N/A hood until I get paint work done on the turbo hood and other parts. I keep thinking paint is going to happen and it hasn't yet.)

Other than obvious things where can I start looking for a cure?

Flushing radiator and cooling system. Should I flush the heater core seperately?
Testing the radiator cap. What pressure cap should a S5 13B T have?
Possibly a clogged oil cooler?
I have air pump removed and so far only a single belt alt pulley. I had a dual belt pulley with my last alt but usually only used one because of belt slipping. Never had issues with heating.

The engine parts and car did sit for almost a year while the rebuild happened. Is it possible I've got a clogged cooling system or oil cooler? I have both oil and water temp gauges and oil temps seem to be where they should be.

RETed · 05-27-2012, 08:46 AM

Quote:

Originally Posted by JustJeff

I'm having overheating issues with the engine.

Is this something that just started to happen?
Was the system working fine prior to this?
Any changes to the cooling system?

Quote:

Here is what I've noticed so far with normal driving (not driving it hard as I'm still breaking in the engine). Temps will keeping rising and rising and when they start to pass 220 I'll pull the car over and either let it idle with the efan running and hood up or turn off the engine but let the efan run and every so often turn the engine on to cycle what is in the radiator back into the engine.

Just to eliminate the obvious...
Is the fan pulling air in the correct direction?

Quote:

N/A hood was being used. While I've been driving to avoid boost as much as possible. The Hallman MBC is set to zero boost, but I need to watch how I'm driving. The OEM wastegate simply can't fully bypass. I thought that perhaps because the MBC was not allowing the engine to be in vacuum that it was contributing to heat. By that I mean it may be purging as much of the pressure as it can, it's also trying to keep pressure at zero. That perhaps rather than having vacuum having zero pressure is still pressurized compared to vacuum and thus creates heat. That theory was partially blown out of the water, I put a turbo hood on it yesterday hoping to see lower temps...and did not. (Before it is said, I'm using N/A hood until I get paint work done on the turbo hood and other parts. I keep thinking paint is going to happen and it hasn't yet.)

Just a side note...
Any type of boost control is going to end up as a bleed-off system
This means that it's next to impossible to get the boost to "zero".
You can only adjust boost down to the base spring pressure - which is most cases is going to be about 7psi - 10psi on an FC turbo with an open exhaust.

Quote:

Other than obvious things where can I start looking for a cure?

Flushing radiator and cooling system. Should I flush the heater core seperately?
Testing the radiator cap. What pressure cap should a S5 13B T have?
Possibly a clogged oil cooler?
I have air pump removed and so far only a single belt alt pulley. I had a dual belt pulley with my last alt but usually only used one because of belt slipping. Never had issues with heating.

Check to see if the radiator is OK:
Get engine warmed up and then check the entire area of the radiator core to see if heat is even; if there are localized spots that are cooler, you have a bad radiator (core).
Stock rated radiator cap is for about 0.9 bar or about 13psi.
I doubt the problem is with the oil system or the oil cooler - do you have an oil temp or oil pressure gauge?

Any reason you're not running double belts?
You really should be running two.
At low RPM's (under 3kRPM), the belt should not be slipping.
If the belt is slipping, it'll be obvious - you can see the pulley slip, and / or hear it slip.
You might also see a lot of excess black dust around the area of the pulleys where the belt is disintegrating.

-Ted

JustJeff · 05-28-2012, 05:28 PM

Quote:

Originally Posted by RETed

Is this something that just started to happen?
Was the system working fine prior to this?
Any changes to the cooling system?

Just to eliminate the obvious...
Is the fan pulling air in the correct direction?

Just a side note...
Any type of boost control is going to end up as a bleed-off system
This means that it's next to impossible to get the boost to "zero".
You can only adjust boost down to the base spring pressure - which is most cases is going to be about 7psi - 10psi on an FC turbo with an open exhaust.

Check to see if the radiator is OK:
Get engine warmed up and then check the entire area of the radiator core to see if heat is even; if there are localized spots that are cooler, you have a bad radiator (core).
Stock rated radiator cap is for about 0.9 bar or about 13psi.
I doubt the problem is with the oil system or the oil cooler - do you have an oil temp or oil pressure gauge?

Any reason you're not running double belts?
You really should be running two.
At low RPM's (under 3kRPM), the belt should not be slipping.
If the belt is slipping, it'll be obvious - you can see the pulley slip, and / or hear it slip.
You might also see a lot of excess black dust around the area of the pulleys where the belt is disintegrating.

-Ted

The heating issue has been going on since rebuild was completed. I've noticed it more because I have been driving it further distances...before the car would drive to get errands. Maybe 10 min drive tops with intervals as long as half hour between the next destination. I was having issues with the efan blowing fuses so I thought temps were related to the fan going out on me. Efan wiring has been corrected, it is working as it should..and pulling air through the radiator.

I've had it parked for about a month now. Not related to heat issues, but I sent my injectors off to be cleaned and have in general been tired of working on it....so it sat.

I'm going to try a yoohoo belt and see what that does for temps. I'm not sure if I have slipping or not. The engine does make a noise it did not previously...but doesn't really sound like belt slipping. I previously had an FD alt and dual pulley. I could never get a matched pair that actually matched...I know slipping sound and this isn't quite it. It's almost like a chirping noise...which could be mild slipping and might only effect things once it's NOT idling.

I do not see it slipping, or have any dust, etc.

Reason I don't have dual belts is because I just got the 140 amp S5 alt and have not sourced one yet. I know the obvious places to get them, BUT I'm wanting to get an overdrive pulley. Yes, overdrive. The modded alt only sees 14v when rpms are above 1k or so. I'd like to find a dual pulley a little bit smaller than stock. Just haven't had time to research and find one.

One factor I had not considered before my post. I had the pulleys powder coated. I would not be at all surprised if that is a factor in slipping. I have a yoohoo belt ordered from Napa. I have read the arguments for and against. My plan is to see if single belt is a factor with my problem. If I have to I'll get an OEM sized dual pulley, but like I said I'd prefer overdrive so charging at idle. I'll report back findings.

I'll also be buying a temp gun to test my radiator...see if I have even temps.

For the oil cooler and such. I do have both aftermarket temp and pressure gauges. The pressure gauge I bought used and I think they gave me the wrong sender. According to tech support the gauge is registering that it is not plugged into the sender...but it is. The craptastic OEM pressure gauge reads about normal and the same as pre-rebuild. Oil temps seem normal. They rise slower than water. I'm not sure numbers off the top of my head, but it never struck me as out of line. Next time I'm driving it I'll get some numbers for both.