| Author |
Message |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 124
Registered: 7-2003
| | Posted on Thursday, August 28, 2003 - 4:23 pm: | |
They're one of the best time savers for many forms of diagnosis....
find which cylinder misfires in seconds by pointing it at the exhaust header pipe. Good strong cylinders get the pipes to around 180 centigrade at idle, poor ones will be down to 50-60
Check your brake performance......are your discs getting too hot for the pads you're using, or more likely, are you getting the race pads you got cheap hot enough!! |
Frank Parker (Parkerfe)
Advanced Member
Username: Parkerfe
Post Number: 2873
Registered: 9-2001
| | Posted on Thursday, August 28, 2003 - 4:19 pm: | |
When I was trouble shooting the cooling system on my Boxer I bought an infrared temp sensor/gun to check the accuracy of my car's gauge($79.00). It showed that the gauge in my car indicated about 5c high. It's a great tool to have around the garage. You'll be surprised just how hot the headers get ! |
Henryk (Henryk)
Intermediate Member
Username: Henryk
Post Number: 1116
Registered: 8-2001
| | Posted on Sunday, August 24, 2003 - 9:34 pm: | |
Phil: Until you suggested it, I never thought of leaving the pressure gauge on the tank and watch it climb, as the engine warms up. This seems like a VERY good way to check the overall cooling system of a car.
Thanks for this tip. |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 100
Registered: 7-2003
| | Posted on Sunday, August 24, 2003 - 9:28 pm: | |
Good on ya H |
Henryk (Henryk)
Intermediate Member
Username: Henryk
Post Number: 1115
Registered: 8-2001
| | Posted on Sunday, August 24, 2003 - 8:54 pm: | |
Well, I'm done. I filled and bled the system....started the car......had the pressure gauge attached to the radiator tank.
Temperature started to go up, to 80 deg C, then the rise became VERY slow.......due to the thermostat opening up. The pressure was slowly rising to about 5 PSI.
I had to wait a while till the fans kicked in......at just under 90 deg C (per gauge in car).......with the pressure at 11 PSI. Once the fans kicked in, and off, the pressure dropped to about 9 PSI. This cycle kept repeating itself.
So, it would seem that the system is now working fine?
It would seem to me that the pressure in the system should never get to the opening pressure of the cap......this will only cause loss of coolant, as I have experienced. Hence, the opening cap pressure is just there in an emergency, when something goes wrong, and the pressure exceeds that of the cap.
Wow......did I learn a lot!!!!!
Thanks to all for your help.
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Henryk (Henryk)
Intermediate Member
Username: Henryk
Post Number: 1114
Registered: 8-2001
| | Posted on Sunday, August 24, 2003 - 7:47 pm: | |
I hope I have solved the problem. I went to Chicago this weekend, with the new OTC coolant sensor......fans kicked in at 97 deg. C.......TOO high......well that is enough for generic sensors. Fortunately, the trip was all highway and the temp stayed at 90 deg C for most of the way....it did get to 97 in the city, in traffic, but never over.....outside temp was about 90 deg F.. Coolant would drain when stopped, but eventually stopped......when it reached a certain level.....I didn't add to it, since it would only drain that too.
Some have recommended going to an 80 deg C sensor, which I considered. However, the thermostat only begins to open at 80 deg...fully opens at 85 deg C, so why have a sensor that will kick in the fans at the same time......doesn't make sense to me....it seems that the fans would run MOST of the time. I conluded that the sensor should be higher than 80 deg, but lower than the 97 deg.C, which is too high. There is NO such generic sensor. I went to Continental and bought a new F sensor......it opens at 86 deg C. .....Ferrari IS smart!!!!!
I concluded that the higher temp. caused too much pressure and expansion of the fluid, hence the overflow. If someone wants to put in a sensor at 80 deg C, then one should also put in a LOWER thermostat......one can only guess where one of these can be found. I know that engines are designed to run at a cerain temperature to be "efficient".....too cool, or too hot, is not good. Since I haven't read anything of a recall by Ferrari on this, I will assume that a running temp of 80-85 deg C is correct......having the fans kick in at 86 deg C makes a lot of sense to me.
It took me 45 minutes to remove the lower bumper, change the sensor, and replace the bumper.....I have it down-packed. If anyone wants to know, then let me know......I took pictures.
I will now re-fill the coolant, and take Phil's advice on checking the pressure as the car warms up. |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 91
Registered: 7-2003
| | Posted on Saturday, August 23, 2003 - 6:45 pm: | |
Sorry Henry, didn't know you have BBi. Carb cars fans are in front, BBi behind. So just plain bad advise from me...especially the fingers in the blades bit!
You should fit a cooling system pressure tester to your tank. Don't pump it up, but start the engine and observe the pressure increase as it warms up.
If the pressure gets to 20lbs, 1.5 Bar then release the pressure as you may damage something, but if everything is fine it should build to about 12lbs, 0.8 bar until the fans kick in.
If your pressure does go way up, it's possible you have a problem with headgasket, or simply an air lock that's causing boiling.
The cooling tester kit's usually have a cap tester, so regardless of whether it's a new cap, test it anyway. It should blow off at the stated pressure 0.9/1.1Bar? |
Henryk (Henryk)
Intermediate Member
Username: Henryk
Post Number: 1108
Registered: 8-2001
| | Posted on Thursday, August 21, 2003 - 6:04 pm: | |
Thanks Dave: I found it.
Now if someone can tell me how to fix the radiator tank, so it doesn't push the coolant through the cap, and over-flow tube. Can it be because of the increased temp, due to the high temp sensor, thus increased pressure? |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1700
Registered: 5-2001
| | Posted on Thursday, August 21, 2003 - 5:24 pm: | |
Henryk,
The low temp thermo switch is NOT a stock, factory oem product, it is aftermarket. VW wants the higher temp one for emissions or something. Anyway, check the Parts & Service tab on this site and check under the section for "308 cross referenced parts" or something like that. They list a source to get it. Really, ANY VW aftermarket parts house will have them, just make sure you get the two pole version, not the three pole. Basically ask for the one for a 70's era Rabbit. |
Henryk (Henryk)
Intermediate Member
Username: Henryk
Post Number: 1107
Registered: 8-2001
| | Posted on Thursday, August 21, 2003 - 5:12 pm: | |
Thanks for your answers.
Phil: The fans are "behind" the radiator, and do in fact PULL the air through. They do rotate in the right direction.
If someone can give me that VW low temp sensor part #, I would appreciate it.
JRV: That is the way I bled the system.
It seems that I have 2 problems: The sensor switch is the high temp one, and not the low......the manual states 183 degrees F is the temp when the fans should go on......so a sensor switch set for 180 degrees is preferred over the 197 degrees switch. The other problem is improper sealing of the radiator cap......bad tank? |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 83
Registered: 7-2003
| | Posted on Thursday, August 21, 2003 - 5:01 pm: | |
Just to clear Malcolm's tips up
On a Boxer, the fans are in front of the radiator, so they should PUSH the air through, as if the car were travelling along forwards!!
If the fans were behind then, PULL. is what you're after.
Get them running and then just put you're finger in the blades to see which way they're going
Just Kidding....use a sheet of paper! |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 2234
Registered: 11-2002
| | Posted on Thursday, August 21, 2003 - 7:17 am: | |
>>Is the switch the same as the 308? Those are VW switches and available in two temps...195/197 and 180. <<
and I agree with David.
There are two switches..normal & low temp...the normal temp is the same as the original Boxer switch...Ferrari buys switches just like we do, only in larger volumes...
Sometimes a trapped air pocket will cause the expunging of coolant...
and to answer your question...Yes, as the temp rises so does the pressure.
Try bleeding the air from cold, rad cap off, heater valves on , continuing to bleed air until just after fans come on. |
Malcolm West (Ferrari_uk_tech)
Junior Member
Username: Ferrari_uk_tech
Post Number: 58
Registered: 7-2003
| | Posted on Thursday, August 21, 2003 - 2:18 am: | |
These may be obvious tips, but have you checked to make sure that the pressure cap is seating properly in the header tank, are both the cooling fans rotating the correct way (pulling the air through the radiator.) You may have a circulation problem, is the water pump moving the water quick enough around the system, could be a semi-blocked radiator - when was the last time the system was flushed ?
MW |
dave handa (Davehanda)
Intermediate Member
Username: Davehanda
Post Number: 1696
Registered: 5-2001
| | Posted on Wednesday, August 20, 2003 - 10:10 pm: | |
Is the switch the same as the 308? Those are VW switches and available in two temps...195/197 and 180. Obviously, get the 180. If it is different than the VW part, then I don't know.... |
Henryk (Henryk)
Intermediate Member
Username: Henryk
Post Number: 1105
Registered: 8-2001
| | Posted on Wednesday, August 20, 2003 - 9:40 pm: | |
Does the pressure in the coolant system increase with increasing water temperature......that is, is the pressure higher at 200 degrees F vs. 183 degrees F?
When driving my Boxer for a while, I notice that there was a loss of coolant.......temp was OK...about 90 C. The coolant came out of the overflow from the radiator fill spout. Only so much would spill, then stop.......but it was about a quart.
I then bought a new cap, with a relief pressure of 1.1 bar (generic). I still had the same problem. Seems like the filler neck is just NOT right for the new cap.
The temp coolant switch then went out on me. I bought a new one (generic). I discovered that it kicked the fans in at about 200 degrees F. The manual states that the fans should kick in at 183 F........so, would this increase my coolant pressure? I feel the temp is too high. When cruising, with new switch, the temp never goes over 90 C, per gauge....so I have good cooling, but I am concerned if stuck in traffic.
The problem with buying generic coolant sensors is that they DON'T list the temp when the fans kick in.......everything is done by year and model of car only.
I don't know what to do now.
Any suggestions?
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