355 Engine temp issue - running too cool?

I broke my cherry working on my father's 355GTS last night - check engine light came on, the OBDII recall was not performed. Yes I know this is a free fix at the dealer which is over 200 miles away so I fixed it myself (Continental AutoSports sent me the OBDII pin free of charge).

After clearing the codes (I'll get to those later) I took the car for a spin to see how everything was running. The oil temp was very steady around 200 degree, the coolant temp not so much. Cruising around at 60mph in 5th or 6th the coolant temp was sitting just above 120 degrees. I slowed down to about 30mph in 3rd and ran the car up to about 80-90 (never going past 6k) a few times. Once I put the engine under load the coolant temp shot up to around 190. Once back under cruise the temp dropped back down to about 120 degrees.

Here is the fun part. My father said his car is randomly idling at various speeds from 1,100 to 2,000 and a few times as high as 3k.
I noticed something, if I pushing in the clutch to allow the car to idle while the temp was low it would be at least 2,000rpm if not higher. After running the car through the gears and getting the temp up to 190 or so, the idle would be close to 1,000rpm. I did this quite a few times and it was consistent.

One of the codes in the computer was P0116 - Coolant Temp Circuit. Is the coolant sensor for the ECU the same sensor for the gauge?

The other codes in the computer:
P1448 - Bypass Valve - there is a resonance while cruising at highway speeds in 5th or 6th. Per other posts that says the valve might be stuck open?
P0102 - Mass Air Circuit (is it safe to clean these?)
P0422 & P0432 - I'm hoping this is related to the MAF or bypass valve. Wishful thinking?

Thanks in advance - in case anyone is wondering I picked up the Inova 3100 OBDII scanner. I was very surprised to see it on the shelf for $97 at a local Farm / Tractor supply store (Fleet Farm). Ferrari is not an option in the menu, but I think that feature is to record the data for multiple cars to look up later. I changed to VW / Alfa and Porsche, the codes were the same.

 

Anyone? No ideas on the cold running issue?

 

1) Water temp sensor for the ECU is located next (to the right of) oil filter housing, has the blue plug on the sensor itself. It is only a $25 to $28 part.
2) The low water temp is probably from a stuck open thermostat. (I had a defective one after a recent major service and had the same exact symptons)
3) MAF, you can attempt to clean it. If you need a new one, search this site for info on a Bosch cross reference to either a Range Rover or BMW E34 540. Much cheaper, and exact same part...just use the Bosch part number on the MAF itself to search online.
4) Bypass valve can stick either open or closed, usually closed. Generally requires replacement. If it rattles, that is a sign it may be on the way out. Nicks Forza Ferrari (sponsor) sells a lower cost replacement made by Capristo. It requires a minor amount of wiring and vacuum hose modification, but looks to be a better part than the oem. I ordered one, but have not received it yet.

 

Thanks 355 - looks like a coolant flush / thermostat replacement is in the near future.

If my thought process is correct this could also clear up the CAT error code since right now under cruise it's running too rich. Since I cleared the codes it's been driven about 300 miles with no CEL.

 

New thermostat is in (pics will be posted of the job eventually )

Now cruising down the highway at 70ish.....the temp gauge is dead center between 120 & 190 degrees. This still seams too cold, I don't even want to think about the new thermostat being defective. Yes I feel very stupid for not testing the new one first in a pot of water. No gold star for me today.

The idle problem seams to be gone, every now ant then it idles up to 1,250 - 1,500 for a few seconds then back down to just under 1,000rpm.

Am I being too picky or do you guys thing something else is wrong?

 

For the idle issue, use some electrical contact cleaner, and clean the connectors to the MAF, idle control motor, and temp sensor on the air intake Y pipe. You might even remove the idle control motor and flush it out with some carb cleaner.

The water temp you describe is normal for 60 to 70ish ambient outside temps at freeway speeds. It depends on outside temp, but my car can be as low as 160 on a cold day, to as high as 180 driving on freeway. Temp needle will be straight up (around 190 to 200) in traffic or idling.

 

Sounds like I'm on the right track then. I've been down the road with annoying idle issues on other cars (came close to shooting my Audi few years back...).
I wanted to make sure I had the temp where it should be before trying to chase anything else down. The old thermostat was stuck open (alsmot couldn't tell looking at it) but the gap was enough to keep the temp around 120 or under unless the car was driven spiritedly.

Since I had the back of the intake off to do the trans fluid, I used some CNC MAF cleaner on the maf.

Ug, possibly another car in under my wing with an idle motor issue...... I hate those things!!