 no wonder my car ran hot... |
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| stecz |
 May 4 2004, 10:43 PM
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#1
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Member  Group: Members Posts: 61 Joined: 20-February 04 From: Cedar Park, TX Member No.: 1,688  |
I've been having trouble with my '73 2.0 running hot... while I was under it I realized that one of the heat exchangers doesn't have the heater hose attached, so it just allows air to escape. I temporarily plugged the hole and low and behold it now doesn't run as hot (210 after 30 minutes of 80mph highway) and it cools down quickly when I slow down.
moral of the story... check the stinkin' obvious... |
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Replies(1 - 19)
| Bruce Allert |
May 4 2004, 10:55 PM
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#2
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Hellions asleep Group: Members Posts: 3,289 Joined: 19-March 03 From: Eagle Creek, Orygun Member No.: 441 Region Association: Pacific Northwest |
It's fun to see wassup & under there, huh?
I like to put the teener on the ramps & lay under it. I just stare up at all the amazing stuff. (IMG:style_emoticons/default/smoke.gif) I find a lot of things to either fix, upgrade or just monkey around with. These lil cars are so cool (IMG:style_emoticons/default/beerchug.gif) .....b |
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| Rockaria |
May 5 2004, 08:13 AM
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#3
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ZippidyDoDah... Group: Members Posts: 817 Joined: 2-May 03 From: Southwest, USA Member No.: 645 Region Association: None |
Maybe I am just slow, but how would a Heat Exchanger Heater hose help cooling? some air runs from the main pully fan through the shroud to the heat exchangers. Then out a hose to the heater flapper box. If the box is in the off position it just vents the hot air under the engine. If the Flapper is open it vents the hot air to the cockpit. Now, Air can also run from the electric fan through hoses into the top of the exchangers and out the other hose to the cockpit. If you plugged that hose on the bottom to the flapper, wouldn't it get really hot by trapping hot air in the exchangers?
Anyone? |
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| tat2dphreak |
May 5 2004, 08:23 AM
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#4
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stoya, stoya, stoya Group: Benefactors Posts: 8,797 Joined: 6-June 03 From: Wylie, TX Member No.: 792 Region Association: Southwest Region  |
QUOTE(Rockaria @ May 5 2004, 08:13 AM) Maybe I am just slow, but how would a Heat Exchanger Heater hose help cooling? some air runs from the main pully fan through the shroud to the heat exchangers. Then out a hose to the heater flapper box. If the box is in the off position it just vents the hot air under the engine. If the Flapper is open it vents the hot air to the cockpit. Now, Air can also run from the electric fan through hoses into the top of the exchangers and out the other hose to the cockpit. If you plugged that hose on the bottom to the flapper, wouldn't it get really hot by trapping hot air in the exchangers? Anyone? (IMG:style_emoticons/default/agree.gif) I don't have any heater stuff hooked up, never will either... |
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| Joe Bob |
May 5 2004, 08:59 AM
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#5
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Retired admin, banned a few times Group: Members Posts: 17,427 Joined: 24-December 02 From: Boulder CO Member No.: 5 Region Association: None |
The fan moves air over the cylinders and oil cooler. The air assists the oil in cooling the engine and oil....
When a loose or disconnected heater hose allows air to escape the engine/oil temp goes up. Doesn't matter whether the heater is on or not. When connected the air is a closed circuit and works as designed. When a heater hose has a gross leak......the cooling air wants OUT....the effeciency of the air flow over the heads and oil cooler are disrupted. When the heater is ON and the hoses are connected with no leaks, the flow is still regulated and the cooler and cylinders get their fair share of cooling. Plus the ambient temp is lower assuming that you use the heat when it's actually cold out.... <_< |
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| Rockaria |
May 5 2004, 09:07 AM
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#6
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ZippidyDoDah... Group: Members Posts: 817 Joined: 2-May 03 From: Southwest, USA Member No.: 645 Region Association: None |
QUOTE(mikez @ May 5 2004, 08:59 AM) When connected the air is a closed circuit and works as designed. My Flapper box vents hot air under the engine when the heater is OFF. So your saying it should not do this? |
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| Part Pricer |
May 5 2004, 09:20 AM
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#7
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Believe everything I post Group: Benefactors Posts: 1,825 Joined: 28-December 02 From: Danbury, CT Member No.: 35 |
I'm with the slow guys here as well. Maybe we should get together and get a short yellow bus we can ride in together. (IMG:style_emoticons/default/unsure.gif)
I've got HEs on my car, but no flapper boxes, heater hoses, nuthin. I have not had a problem with running too hot. And, I can't see how the heating path affects the engine cooling. (IMG:style_emoticons/default/confused24.gif) |
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| Mark Henry |
May 5 2004, 09:30 AM
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#8
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
QUOTE(Rockaria @ May 5 2004, 06:13 AM) how would a Heat Exchanger Heater hose help cooling? some air runs from the main pully fan through the shroud to the heat exchangers. Then out a hose to the heater flapper box. Anyone? Most likely he also fixed the flapper boxes at the same time. If the hoses are off and it running wide open, a lot of air is escaping, thus having a major effect on cooling. QUOTE If the box is in the off position it just vents the hot air under the engine. It does have an over pressure valve, but very little air should be coming out of it. QUOTE If the Flapper is open it vents the hot air to the cockpit. Now, Air can also run from the electric fan through hoses into the top of the exchangers and out the other hose to the cockpit. If you plugged that hose on the bottom to the flapper, wouldn't it get really hot by trapping hot air in the exchangers? Not an issue. When it comes to the heating system, use it or lose it, by plugging it proper. |
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| Mark Henry |
May 5 2004, 09:34 AM
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#9
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
QUOTE(Paul Heery @ May 5 2004, 07:20 AM) I've got HEs on my car, but no flapper boxes, heater hoses, nuthin. I have not had a problem with running too hot. And, I can't see how the heating path affects the engine cooling. (IMG:style_emoticons/default/confused24.gif) Your oil temps may be OK, but I'll bet your cooking the heads. Plug it! |
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| tat2dphreak |
May 5 2004, 10:10 AM
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#10
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stoya, stoya, stoya Group: Benefactors Posts: 8,797 Joined: 6-June 03 From: Wylie, TX Member No.: 792 Region Association: Southwest Region |
QUOTE(Mark Henry @ May 5 2004, 09:34 AM) QUOTE(Paul Heery @ May 5 2004, 07:20 AM) I've got HEs on my car, but no flapper boxes, heater hoses, nuthin. I have not had a problem with running too hot. And, I can't see how the heating path affects the engine cooling. :confused: Your oil temps may be OK, but I'll bet your cooking the heads. Plug it! I have plugged the hole at either side of the impeller... are these the ones you are referring to? |
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| stecz |
May 5 2004, 10:39 AM
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#11
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Member Group: Members Posts: 61 Joined: 20-February 04 From: Cedar Park, TX Member No.: 1,688 |
When the engine was running, air was exiting out the bottom side of the fan housing, through the heat exchanger and out the hole that should have had a hose attached.
My assumption is that the air was following the path of least resistance, so alot was exiting out the hole instead of through the oil cooler and over the heads. As a by product, I think the heater is working better (the one side is hooked up)... I was thinking about just disconnecting and going with headers since it worked so crummy, but I may have changed my mind. |
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| SirAndy |
May 5 2004, 10:56 AM
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#12
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Resident German Group: Admin Posts: 41,658 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Rockaria @ May 5 2004, 08:07 AM) My Flapper box vents hot air under the engine when the heater is OFF. that's where your logic is wrong (IMG:style_emoticons/default/wink.gif) when the heater is turned off (no fan pushing air through) there's almost NO air going through the HE's and only very little hot air escapes through the opening at the flapper box. on the other hand, if you have the heater on, (lots of air pushing through the HE's) and a (or both) hoses on the flapper box is NOT attached, you dump all that hot air under the engine! Andy |
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| McMark |
May 5 2004, 11:01 AM
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#13
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
If you don't have the flapper boxes/ hoses connected then remove the ducting that runs from the impeller fan housing to the HEs and plug those holes in the impeller housing with something. You have to get creative there, but they must be plugged.
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| tat2dphreak |
May 5 2004, 11:31 AM
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#14
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stoya, stoya, stoya Group: Benefactors Posts: 8,797 Joined: 6-June 03 From: Wylie, TX Member No.: 792 Region Association: Southwest Region |
QUOTE(markd@mac.com @ May 5 2004, 11:01 AM) If you don't have the flapper boxes/ hoses connected then remove the ducting that runs from the impeller fan housing to the HEs and plug those holes in the impeller housing with something. You have to get creative there, but they must be plugged. it looks like the PO filled this with some spray insulation, or ugly welding, or some HARD crap! I never had the hoses, flapper, or anything else... so, am I ok? |
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| Rockaria |
May 5 2004, 11:43 AM
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#15
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ZippidyDoDah... Group: Members Posts: 817 Joined: 2-May 03 From: Southwest, USA Member No.: 645 Region Association: None |
Okay here goes... I always assumed the small ducting from the impeller fan hosing to the heat exchangers was to direct some air over the heat exchangers all of the time. Possibly to cool the exhaust pipes a bit, and to ad a little heat if the flapper box is opened a little. Then the electric fan came on when the flapper was full open giving lots of heat to the cockpit.
I assumed if you plugged that impeller fan housing path to the heat exchangers you would overheat the ehaust and exchangers becuase you stopped any circulation in the heat exchangers. So what I am seeing is that you CAN plugg that hole stopping air from going from the impeller house to the heat exchangers and NOT hurt the exhaust system at all by overheating it. Is this right? |
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| SirAndy |
May 5 2004, 12:08 PM
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#16
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Resident German Group: Admin Posts: 41,658 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(Rockaria @ May 5 2004, 10:43 AM) Is this right? most of the cars came with the Passanger side HE plugged from the factory! (IMG:style_emoticons/default/wink.gif) Andy |
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| stecz |
May 5 2004, 03:03 PM
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#17
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Member Group: Members Posts: 61 Joined: 20-February 04 From: Cedar Park, TX Member No.: 1,688 |
most of the cars came with the Passanger side HE plugged from the factory!
Andy ??? So is there a plug that I can get that fits into the HE? Right now it's a total cluge. I was going to grind off the flange that looks like it should attach to the hose and rivet a piece of sheet metal there. |
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| Toast |
May 5 2004, 03:35 PM
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#18
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Not bad for carrying sway bars. Group: Members Posts: 3,377 Joined: 20-January 04 From: Las Vegas Member No.: 1,580 Region Association: Southwest Region |
Paul Heery,
I just wanted to tell you that your avitar is friggin Hillarious! (IMG:style_emoticons/default/laugh.gif) Been wanting to say that for a while now. Thanks for the laugh. |
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| SirAndy |
May 5 2004, 03:41 PM
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#19
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Resident German Group: Admin Posts: 41,658 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
QUOTE(stecz @ May 5 2004, 02:03 PM) So is there a plug that I can get that fits into the HE? there is a factory plug that goes onto the inlet of the HE that sticks out through the engine-tin on top of the engine. get 2 plugs and plug 'em up ... Attached image(s) 
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| Dave_Darling |
May 5 2004, 03:58 PM
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#20
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914 Idiot Group: Members Posts: 14,990 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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Aaahndy, he's talking about the ones down underneath, at the bottom of the fan shroud. The engine cooling fan does indeed push air into the heat exchangers at all times. When the flapper valves are closed, this air (by now hot) gets dumped out underneath the engine. While it is not a ton of air, it is indeed some. Pull up on the heater lever, and stop just before the fan comes on. You'll find that some hot air does come out of the vents. Also, all 73-74 914s came with the passenger's side J-tube blocked (just where your illustration shows, but on the passenger's side). The pax can actually get some heat in those cars, which also shows that the engine cooling fan does move some air through the exchangers.
I doubt it's enough for its lack to cause overheating. But if you have no heat exchangers, it's a good idea to plug up the holes in the bottom of the fan shroud anyway. --DD |
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