| Author |
Message |
James Selevan (Jselevan)
Member
Username: Jselevan
Post Number: 370
Registered: 6-2002
| | Posted on Monday, February 24, 2003 - 10:26 pm: | |
Soft, flexible, approximately 1 cm outside diameter. (I'm not referring to anyone's anatomy).
Jim S. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 518
Registered: 5-2001
| | Posted on Monday, February 24, 2003 - 7:59 pm: | |
James,
What was the size of this vacuum hose?
Dave |
Ron Shirley (Easy_rider)
Junior Member
Username: Easy_rider
Post Number: 224
Registered: 12-2002
| | Posted on Monday, February 24, 2003 - 6:59 pm: | |
Steve, I had a very similar problem in my Mondial with the 328 engine. I got heat at idle but when moving got none or intermittent heat. We replaced the hot/cold potentiometer next to the fan control on the center console but that did not help.
Finally it was fixed by replacing a heater pump valve on the driver's side of the engine (not the side of the timing belt). This part cost about $365 and $100 to install.
I can email a picture of the valve if you want. I do not know the part number and could not figure it out on the Ferrari UK site. |
James Selevan (Jselevan)
Member
Username: Jselevan
Post Number: 367
Registered: 6-2002
| | Posted on Monday, February 24, 2003 - 1:22 pm: | |
Yes- they are on the Testarossa. My defroster would not work until I found and repaired the cracked vacuum hose. It was cracked at the nipple connector in the engine bay. I simply cut off an inch, re-connected to the reservoir nipple, and problem solved.
Jim S. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 515
Registered: 5-2001
| | Posted on Monday, February 24, 2003 - 11:47 am: | |
Actually James, is it possible the heater core valves are ALSO vacuum assisted in their operation? If so, then your idea may have merit....
Hmmmm |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 512
Registered: 5-2001
| | Posted on Sunday, February 23, 2003 - 8:36 pm: | |
The duct thing probably not applicable to the 328. The duct is open, as I can feel air coming through, just cold air. If it is closed, no air comes out whatsoever. |
James Selevan (Jselevan)
Member
Username: Jselevan
Post Number: 358
Registered: 6-2002
| | Posted on Sunday, February 23, 2003 - 8:28 pm: | |
David - actually quite simple. Look in your engine bay for a small diameter, flexible, long rubber tube that terminates in a cylindrical plastic or metal can. Inspect the tube for cracks at the junction point. Two of my cars suffered this malady. Easy to fix. Cut off an inch of tubing and re-insert onto the nipple. This, of course, presupposes that you have such a vacuum assist control under the dash, and that this is the source of the problem. Both are speculative.
Jim S. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 511
Registered: 5-2001
| | Posted on Sunday, February 23, 2003 - 8:24 pm: | |
Steve Ma,
I tried bleeding from the back and about 3 seconds worth of air came out, and rather feeble at that, compared to the 7 second blast from the front.
The vacuum thing sounds interesting, but beyond my backyard mechanic skills... |
James Selevan (Jselevan)
Member
Username: Jselevan
Post Number: 357
Registered: 6-2002
| | Posted on Sunday, February 23, 2003 - 7:39 pm: | |
While not familiar with the 3x8 series, the Testarossa has a vacuum system that moves ducts in the air-conditioning/heater system under the dash. The vacuum is generated by the intake manifold through a reservoir in the rear of the engine bay (small cylindrical can). If you have a leak in your system, such as a small hole or crack where it attaches to the reservoir, you may only pull sufficient vacuum when under load - thus explaining the heat when driving but not at idle. Something to think about. Check your vacuum line that supports air-conditioning/heating functions (if there is such a thing in the 3x8 series).
Jim S. |
Paul Hill (348paul)
Junior Member
Username: 348paul
Post Number: 58
Registered: 12-2002
| | Posted on Sunday, February 23, 2003 - 4:31 pm: | |
Dave,
Just throwing a few things up in the air.....
If there is no difference in the mechanics of the heating system between stationary and moving there may be a chance that momentum is playing a part?
I don�t know the 328 system that well and can only suggest that if there is a heater valve or some other valve that might have a loose gate (or whatever they use in the system) that might move once the car is underway causing momentum. The pumps are obviously only circulation pumps so no real pressure is involved � What about debris in the pipeline to the heater matrix?
Interesting one!
Keep us all posted!
Paul
|
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 510
Registered: 5-2001
| | Posted on Sunday, February 23, 2003 - 1:06 pm: | |
Steve,
Here are the answers:
Hot
Cold
?
Cold
A couple things: If I start the car from cold and let it idle, though engine temp comes up, I will never get heat from the registers until I start off. And if I am moving them come to a stop, after a few minutes, the heat temp out of the registers will begin to drop. When driving around, I can get the registers to blow very hot if set to max.
BTW, it did this both before and after waterpump rebuild by my mechanic, who presumably went through the bleed process (which make sense, since I got almost no air out of the radiator bleed screw).
Dave |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1430
Registered: 1-2001
| | Posted on Sunday, February 23, 2003 - 10:03 am: | |
Dave -- Does "standing still/moving" mean it (no heat) relates to the coach ground speed or engine RPM? Describe your symptom for these conditions:
vehicle moving, engine running moderately (2500~3000 RPM) = hot/cold?
vehicle moving, engine idling = hot/cold?
vehicle stopped, engine 2500~3000 RPM = hot/cold?
vehicle stopped, engine idling = hot/cold?
The 328 parts catalogue on the FerrariUK parts site (which is a fabulous Owner information resource IMO -- worth the hassle to get access thru the F Owner's Site and get IsoView working) shows that your 328 uses the same thermostat housing/bleed screw as the 308s so it wouldn't hurt to crack it open and see what comes out (engine off with the cooling system slightly pressurized). Not something that needs to be done frequently, but not never either.
|
Greg Rodgers (Joechristmas)
Member
Username: Joechristmas
Post Number: 674
Registered: 3-2001
| | Posted on Sunday, February 23, 2003 - 7:16 am: | |
Dave, I have seen this on other cars too. I am sorry that I don't know the answer but my friends car does the same thing. I am anxious to hear what the problem is.
|
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 509
Registered: 5-2001
| | Posted on Saturday, February 22, 2003 - 10:58 pm: | |
Okay, here's a strange one. My 328 will not blow hot air out of the heater ducts if the car is standing still. If I am moving, plenty of heat. I just tried bleeding the radiator a minute ago, and just a tiny bit of air came out (7-8 seconds worth).
Should I try bleeding from the thermostat flange? Not sure where this is...by the thermostat I guess? :-)
Dave |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1429
Registered: 1-2001
| | Posted on Saturday, February 22, 2003 - 5:39 pm: | |
Yes, the later thermostat housing with the bleed screw is a definite improvement, but you can still do some air bleeding in that area if you loosen the hose clamp and gently work something like a short awl as high up as possible in-between the radiator hose section and the thermostat housing to open up a "leak" -- probably a little messy, but functionally should get you most of the way there IMO. |
Steve (Steve)
Member
Username: Steve
Post Number: 307
Registered: 2-2001
| | Posted on Saturday, February 22, 2003 - 2:22 pm: | |
Steve got it for the choke on light and you're right. I must have hit it while moving the heater levers. Ok as for the bleed ports I only have 1 which is located on the top right side of the raditor. There is no bleed screw on my thermostat housing. Must be an old style set up. I could see where that would be advantagous in the bleeding process because when I squeeze the upper rad. hose it feels like there in nothing in it and also the heater cores must have air in them because I get no heat yet. I would have thought that if I get water out of the rad. top bleed screw then the rad would be full. Maybe I need to get a new tstat housing ? |
Philip Airey (Pma1010)
Junior Member
Username: Pma1010
Post Number: 142
Registered: 7-2002
| | Posted on Saturday, February 22, 2003 - 11:43 am: | |
Steve
You recall correctly. The upper right is a choke indicator, and mine is also as flaky as you remember. It is yellow as I recall.
Philip |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1428
Registered: 1-2001
| | Posted on Saturday, February 22, 2003 - 11:37 am: | |
Are you referencing the exact OM for your version '77 308GTB? IIRC the upper right lamp is the "choke on" warning light for the carbed B/S (and became "spare" only on the later injected 2-valves). Verify the cabin choke lever is in it's home position (The "choke on" lamp is activated by a rather flaky grounding switch arrangement hanging off the side of the cabin choke lever assembly inside the tunnel -- it can get mangled by the nearby cabling if the cabling's not well routed).
By "bled" -- both places? Was/is there a vent hole in the thermostat flange? |
Steve (Steve)
Member
Username: Steve
Post Number: 306
Registered: 2-2001
| | Posted on Saturday, February 22, 2003 - 11:21 am: | |
OK just put in the rebuilt WP I had done by the Flying Dutchman. Pump looks good and no leaks after install. Now a few common questions here. Drained and refilled the cooling system and did the 1st bleed of air. ran the enging and only got temp gage to 165 and doesn't want to get hotter but the rad seems hot and no heater heat. Assume more air in the system?? I'll bleed it again later. Also strange thing happened the upper right dash light now lights up. The OM says its a spare? Does anyone know where this is triggered from? Never had this light before. And last does anyone have the correct bolt size to replace the studs on the front (front of car side) timing belt cover. Thanks Steve |