Temprature - is this normal? - Page 7 - Alfa Romeo Bulletin Board & Forums
 56Likes
Reply
 
LinkBack Thread Tools Display Modes
post #91 of 103 (permalink) Old 08-10-2019, 09:52 PM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,980
I know that this is treating the symptoms rather than the cause but Serpent Autosport sell a louvered tea tray that helps ventilate the engine compartment and IMO looks pretty good.
Gepetto likes this.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is online now  
Sponsored Links
Advertisement
 
post #92 of 103 (permalink) Old 08-10-2019, 10:29 PM
Registered User
 
sportiva's Avatar
 
Join Date: Aug 2005
Location: Newcastle Australia
Posts: 503
Do you still have the Milano fan or the original twins to substitute for the Spal setup, the twins would be better because they allow the system to work as designed one fan for the air-con when used and two fans for the thermal dynamics of the cooling system.
If you remove the thermostat your self to test it, this would be a good time to check flow through the radiator and engine block simply putting a garden hose into the radiator hose and watch how it flows out through the thermostat housing. (if you live in an apartment block this might not be ideal)

Glen 3.0 GTV6 2.0 156 JTS
EX 1.2 Alfasud. 1.8 and 2.0 Alfetta's 2.5 Alfa75
sportiva is offline  
post #93 of 103 (permalink) Old 08-11-2019, 12:21 PM Thread Starter
Registered User
 
Gepetto's Avatar
 
Join Date: Dec 2014
Location: Queens, New York
Posts: 520
Garage
@sportiva I do have the original twins to substitute. I wonder if I can take the Spal fans out of the current shroud entirely and put them into the frame of the originals. The Spal fans move much more air (shroud or no shroud) than the originals. For checking flow, you mean literally sticking a garden hose to one of the hoses that hooks up to the thermostat?
@alfaparticle I've thought of that. What happens when it rains, though? Water must get through into the engine bay...
Gepetto is offline  
Sponsored Links
Advertisement
 
post #94 of 103 (permalink) Old 08-11-2019, 01:29 PM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,980
The louver openings face backwards so if you are in motion not much rain will get in there. I once drove my GTV6 in the rain and I had no problems.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is online now  
post #95 of 103 (permalink) Old 08-12-2019, 09:48 PM
Registered User
 
sportiva's Avatar
 
Join Date: Aug 2005
Location: Newcastle Australia
Posts: 503
Pull the thermostat housing top off remove it from the radiator hose then insert the garden hose into rad hose use a rag to stop any backflow then watch for rust or debris as it comes through the thermostat lower housing when the water runs clear you can reverse the flow or backflush the system. This is a flow test to check for a major blockage as even with some of the tubes blocked water will still flow around the blocked tubes then on through the system and it is not as good a professional backflush. If the radiator was re-cored only a few years ago the system should be relatively clean with no chunks of rust or calcification flowing through as you flush it.

Glen 3.0 GTV6 2.0 156 JTS
EX 1.2 Alfasud. 1.8 and 2.0 Alfetta's 2.5 Alfa75
sportiva is offline  
post #96 of 103 (permalink) Old 08-20-2019, 04:42 PM Thread Starter
Registered User
 
Gepetto's Avatar
 
Join Date: Dec 2014
Location: Queens, New York
Posts: 520
Garage
Thumbs up Update - almost there!

A quick update on the heat situation with my engine. After checking the ignition timing, it turned out to be way too advanced (13 degrees!). How it got there, I have no idea. After reducing it to 6, and then 4 degrees, it ran quite a bit better and smoother. The temperature also seemed to be better kept nearish 180, though still a little warmer than normal at speed. I'll need to do another open road highway test (which is not easy in the NYC area). Under the limited testing I could do today, the engine temp does not shoot up as rapidly under acceleration. Win!

I can also confirm that coolant flow is adequate and no chunks of rust or debris were circulating in the system.

It seems the Ansa headers and downpipes are radiating an awful lot of heat. Again, while more testing is required, it seems that that's also something that needs to be addressed. I'm thinking of sending them off to Jet-Hot for a ceramic coating. Apparently, they reduce radiated heat by 50%...that can't hurt!

We're almost there guys! Thanks for all your feedback.
Gepetto is offline  
post #97 of 103 (permalink) Old 08-20-2019, 07:28 PM
Senior Member
Gold Subscriber
 
Join Date: Jun 2016
Location: Santa Barbara, CA
Posts: 240
Quote:
Originally Posted by Gepetto View Post
A quick update on the heat situation with my engine. After checking the ignition timing, it turned out to be way too advanced (13 degrees!). How it got there, I have no idea. After reducing it to 6, and then 4 degrees, it ran quite a bit better and smoother. The temperature also seemed to be better kept nearish 180, though still a little warmer than normal at speed. I'll need to do another open road highway test (which is not easy in the NYC area). Under the limited testing I could do today, the engine temp does not shoot up as rapidly under acceleration. Win!

I can also confirm that coolant flow is adequate and no chunks of rust or debris were circulating in the system.

It seems the Ansa headers and downpipes are radiating an awful lot of heat. Again, while more testing is required, it seems that that's also something that needs to be addressed. I'm thinking of sending them off to Jet-Hot for a ceramic coating. Apparently, they reduce radiated heat by 50%...that can't hurt!

We're almost there guys! Thanks for all your feedback.
Hmmm, in general it is overly retarded ignition timing that causes hotter engine temps, but if your engine runs better then that is good. I'd be curious to know the before and after total ignition timing advance, but that's OK.

While it might be the case that the factory cast-iron exhaust manifolds retain more of the exhaust heat, I seriously doubt that whatever additional heat radiated by the aftermarket headers would cause the engine coolant temperature to be warmer at speed. Think about it. There is airflow underneath the car while driving at speed that is flowing along the exhaust system and moving in the opposite direction of the radiator. Any such heat from the headers would be more of an issue at idle/low speed, during which you say the temps are OK.

I would ditch those shrouds completely and report back.
alfaloco and sportiva like this.

Chris A: '81 GTV6 rescued from junkyard, "GT" car/'86 Porsche 944 Turbo track/street car/'73 BMW 2002tii fun street car/'74 Jensen Healey Lemons Rally car!
cda951 is offline  
post #98 of 103 (permalink) Old 08-21-2019, 07:53 AM Thread Starter
Registered User
 
Gepetto's Avatar
 
Join Date: Dec 2014
Location: Queens, New York
Posts: 520
Garage
Quote:
Originally Posted by cda951 View Post
I'd be curious to know the before and after total ignition timing advance, but that's OK.
If I understand you correctly, we were at 13 degrees before TDC, now I'm at 4 degrees. (I did not record advance at higher RPM, just idle... but it didn't look like anything unusual).

If further testing doesn't change anything, then I may just put the old shroud-less twin fans in for a test.

Last edited by Gepetto; 08-21-2019 at 09:38 AM.
Gepetto is offline  
post #99 of 103 (permalink) Old 08-21-2019, 05:08 PM
Registered User
 
Millsy's Avatar
 
Join Date: Aug 2014
Posts: 133
Garage
Gepetto, I'm wondering... what was the air temperature on this day? Also, the thermostat is probably set to open at 83c So, unless I've missed something, your car should run at that temperature as a minimum. Here in Oz (South Australia) we worry when the temp of the car approaches 100c. For those of us old enough to have run cars with water in the radiator boiling point was an issue! However, modern coolants are totally fine up to about 120c. On a hot day (43c Low humidity) I have run my GTV4 at 105-110c with no problems. Though you do need to keep moving. As a cyclist I can assure you that the temperature of the road surface in these conditions is around 60-70c. However, turning on the aircon will add heat: lots of it.
The shrouds are definitely a problem. As would be a failed fan. The air con condenser was installed at an angle in my GTV4. It was a very effectively air blocker.
Have you checked: timing? mixture (a little bit lean will really push up temperature). With regard the GTV6 there are lots of places that air can get in after the MAF and before the chambers as there are lots of rubber parts that routinely perish. This was my first challenge. I have replaced virtually every hose and rubber seal. I'm in the process now of doing all the rubber and gaskets on the inlet tubes. Do you have one of those infra red heat sensor guns? They're like a laser pointer but they measure temperature. I was recently (and still am) dealing with blockages in the idle jets of my GTV4 and i can tell which cylinder is lean or rich simply by the exhaust manifold temp. At 280c it is lean (ie the car is running rough because the jet is blocked again). At 100c it is rich. Check this. Lean = Hot.
A list of leak sites from the MAF to the cyclinder:
The Snorkel can have fine cracks in the bellows or around the junctions with other pipes.
The other pipes can have hidden cracks or just be perished.
The clamps can be loose.
Check every joint, connector or seal on the plenum (there is at least 7 places for air to get in)
Under the Plenum the rubber connectors to the intake runners perish.
The clamps need to be tight.
The intake runners have seals that might be leaking. In my car the nuts on these were not tight. They were done up but way too easy to undo.
The injectors have rubber seals.

You get the picture. I'm an amateur but i'm fairly sure that you can have an OK mixture at idle but when running at speed go lean due to an air leak that opens when the intake pressure is low (ie sucking lots of air).

One final comment. You guys in America make lots of comments about it being really hot and humid. Humid helps heat transfer but not evaporation. Hot humid days conduct more heat away than hot dry days. Cars don't have evaporative cooling like us humans... just saying...
alfaloco and martym00se72 like this.
Millsy is offline  
post #100 of 103 (permalink) Old 08-21-2019, 07:32 PM Thread Starter
Registered User
 
Gepetto's Avatar
 
Join Date: Dec 2014
Location: Queens, New York
Posts: 520
Garage
Hey @Millsy thanks for your thoughts! The ambient temperature on the test runs ranged from 70F (21C) to 100F (38C). Truth be told, this issue has been going on for a while, even with temperatures around 50F (10C). Once the temperature drops below freezing, I have not noticed this issue.

A/F mixture was tested both at idle and under load (from light maintenance throttle all the way to WOT) and it is not lean and hovers at 14.7 under most conditions, and 12ish at WOT. Though I do need to get a heat gun - I don't have one of those...
Gepetto is offline  
post #101 of 103 (permalink) Old 09-16-2019, 12:38 PM Thread Starter
Registered User
 
Gepetto's Avatar
 
Join Date: Dec 2014
Location: Queens, New York
Posts: 520
Garage
Update - Problem Solved!

Hi All - first I want to thank you for all your input. I'd like to report that, at long last, this "running hot" problem has been solved.

The culprit? A re-cored radiator. You heard me right. I had the original radiator re-cored, and it turns out that for whatever reason, it wasn't cooling the coolant enough to keep the temperature within normal limits. We put on a radiator from a GTV6 that did not have any overheating problems (original fans and all), and now no matter how much I push the car on the highway, the temperature stays at 180. Even better, the temperature only rises slightly in stop and go traffic and never comes anywhere near the dreaded third line (100C).

I think still the car would benefit from having the headers ceramic coated (reducing under-hood temperatures is always a good thing), but it's no longer a pressing issue.

Lesson? Make sure any new radiator you put in your car is exactly like the original.
Gepetto is offline  
post #102 of 103 (permalink) Old 09-17-2019, 06:49 AM
Senior Member
Gold Subscriber
 
Join Date: Jun 2016
Location: Santa Barbara, CA
Posts: 240
I am guessing that new GTV6 radiators are no longer available?

Chris A: '81 GTV6 rescued from junkyard, "GT" car/'86 Porsche 944 Turbo track/street car/'73 BMW 2002tii fun street car/'74 Jensen Healey Lemons Rally car!
cda951 is offline  
post #103 of 103 (permalink) Old 09-17-2019, 07:26 AM Thread Starter
Registered User
 
Gepetto's Avatar
 
Join Date: Dec 2014
Location: Queens, New York
Posts: 520
Garage
Quote:
Originally Posted by cda951 View Post
I am guessing that new GTV6 radiators are no longer available?
That's a good question. OKP seems to have rebuilt ones (to the original specs) as well as aluminum ones. Alfissimo advertises an OEM one but I havne't been able to get in touch on whether it's actual OEM or reproduction.
Gepetto is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome