EGR Question - High Oil Temps

Bus, Microbus, Transporter, Station Wagon, Vanagon, Camper, Pick-Up.

Moderators: Sluggo, Amskeptic

Post Reply
User avatar
ewalt98
I'm New!
Status: Offline

EGR Question - High Oil Temps

Post by ewalt98 » Fri Sep 04, 2015 6:27 pm

Hi all, first post here for me.
I have a stock 82 California air cooled vanagon that has always run hot according to my oil temp gauge.
In diagnosing, I was checking/cleaning the EGR valve, and noticed that when I disconnect the linkage from the throttle, and then open the EGR valve, there is not change in the idle, as Bentley suggests. I did clean it, and the system is intact.
I thought maybe there was a vacuum leak, which might mask the EGR effect, but I can't find one. However, my vacuum readings are a low but steady 11-12.
Any thoughts on that?
Thanks
Eric
1982 Vanagon Westfalia Equiped

User avatar
asiab3
IAC Addict!
Location: San Diego, CA
Contact:
Status: Offline

Re: EGR Question - High Oil Temps

Post by asiab3 » Sat Sep 05, 2015 7:21 am

Hi Eric, and welcome! Congrats on your first post.

How hot is "hot" according to your oil temperature gauge, and where is the sender located?

When you said you "cleaned it," what do you mean, exactly?

Where are your "vacuum readings" taken from, and is that at idle?

Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

User avatar
ewalt98
I'm New!
Status: Offline

Re: EGR Question - High Oil Temps

Post by ewalt98 » Sat Sep 05, 2015 8:42 am

Hi Robbie,
Thanks for the reply.
I have a VDO gauge with the sender in the little 914 plate at the bottom of the crank case. I know the VDO gauges aren't the most accurate. Just got an IR temperature reader yesterday, and, at idle temps, the gauge and IR reader are pretty close. I recorded 124 on the plate, while my gauge read 121. The TII was reading around 240, if that means anything.
My temps over the years have always read around 220-240 on normal drives, and up to 260+ climbing. Last weekend, I pegged the gauge at 300 on a long climb into a head wind. I drive sanely, so 3rd gear at 45-50, but when the temp got really high, I dropped to 2nd and 30.
I rebuilt the EGR system with a new filter years ago, and a few weeks ago, I pulled the valve apart to make sure it wasn't sticking open, and cleaned some of the carbon deposits out. It was pretty clean, and seemed to function properly. The only thing I noticed was the little rubber seal had torn around the shaft, but this is at the leaver side, so I don't know if it makes any difference.
As for the vacuum, I T'd into the main plenum port for the decel valve and fuel pressure regulator.

I also checked the timing (5' ATDC at idle, and 28? at speed), replaced the plugs and wires, and ran most of the FI tests in Bentley while diagnosing a hesitation and bucking issue. That turned out to be the ECU.

The only thing that I've found wrong is the cable recently broke for the warmup flaps, so it is stuck open.

So, everything I've read over the years suggests that with a perfectly stock and tuned engine, I shouldn't ever get over 280 oil temps. So now, I want to figure out why I run so hot.
Oh, a head gauge is on my list.

Eric
1982 Vanagon Westfalia Equiped

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: EGR Question - High Oil Temps

Post by Amskeptic » Mon Sep 07, 2015 6:12 pm

ewalt98 wrote: So, everything I've read over the years suggests that with a perfectly stock and tuned engine, I shouldn't ever get over 280 oil temps. So now, I want to figure out why I run so hot.
Eric
I still don't trust that toy, that VDO aftermarket nonsense.

What do the insides of your valve covers look like? Are the rocker arms and shafts and valve spring retainers all a spattered burnt brown, or can you see the metal still? Is the head aluminum shiny and mildly brown or is it matte brownish/black? Does it smell acrid or sweet?

My favorite spot to IR the case is the diagonal area just inside of the oil filter above the fins. It is slightly out of the air stream. I have read 264* in the heat, but 220 to 240* in normal circumstances.
How much oil is in your engine? Keep it at the full or slightly above. Is your oil cooler clean? Does the left flap (vane) sit on the tin securely when open? Vacuum advance distributor? Vacuum line goes to the throttle plate area? Retard the timing a couple of degrees just for forensics. Bottom of the case clean? This is important. Shiny clean is good. Some hot engines have an inadvertent load on them, like slightly advanced timing, or dragging brakes, or crap sucked into the fan and deposited on the cooler fins where you can't see it.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
ewalt98
I'm New!
Status: Offline

Re: EGR Question - High Oil Temps

Post by ewalt98 » Tue Sep 08, 2015 7:03 am

Amskeptic wrote:or crap sucked into the fan and deposited on the cooler fins where you can't see it.
Colin
I can attest to that. About a year after I bought the van, I burned out #3 exhaust valve. When I disassembled to replace the head, I found some black cloth tape draped over the cooling fins. So, the hot cylinder ran even hotter. That was over 20 years ago, and I can't remember if I also replaced the cylinders at the same time, or not, but I know I did at some point. That was the early 90's.

Went camping this weekend, and before hand, I looked through the spark plug holes, under than engine, and the bottom of the oil cooler. All looked clean from what I could see without taking the tin off. There is some oil on the bottom of the engine, but not caked. The valve covers are pretty clean and black still. Blew some compressed air through the fins in case there was some debris on them.
My VDO never read over 240'sh, and the IR on the oil temp plate read the same. I will try to the area around the filter.

What do you mean by "Does the left flap (vane) sit on the tin securely when open"? Is that the flap with the 90' bend, and how could I check it?

Next on my list, will be to retorque the heads (I did it after a certain number of miles when I replaced heads/cylinders) and check the valves. I am also going to get a head temp gauge.
1982 Vanagon Westfalia Equiped

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: EGR Question - High Oil Temps

Post by Amskeptic » Thu Sep 10, 2015 7:34 am

ewalt98 wrote:
What do you mean by "Does the left flap (vane) sit on the tin securely when open"? Is that the flap with the 90' bend, and how could I check it?
With a warm engine, just close the flaps and let them spring back open. Do you hear the left vane clank down?
Pull #4 spark plug connector and view the vane just back of the plug. Does it appear to be covering the cooler evenly? Run the flap lever and watch how it picks up and drops. You will see if it is warped or the shoulders of the tins are bent.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
SlowLane
IAC Addict!
Location: Livermore, CA
Status: Offline

Re: EGR Question - High Oil Temps

Post by SlowLane » Sun Sep 13, 2015 4:28 pm

ewalt98 wrote: I have a stock 82 California air cooled vanagon that has always run hot according to my oil temp gauge.
In diagnosing, I was checking/cleaning the EGR valve, and noticed that when I disconnect the linkage from the throttle, and then open the EGR valve, there is not change in the idle, as Bentley suggests. I did clean it, and the system is intact.
I thought maybe there was a vacuum leak, which might mask the EGR effect, but I can't find one. However, my vacuum readings are a low but steady 11-12.
Hi Eric. When doing the EGR valve test, make sure your ignition idle stablizer is bypassed, otherwise it may just be fighting with you to keep the idle steady.

If that doesn't do the trick, then your EGR passages might be plugged in the air plenum, which would prevent the exhaust gasses from being introduced.

The little tear in the EGR valve diaphragm isn't good. It will be introducing a vacuum leak or letting the exhaust gasses to leak into the engine compartment.

With regards to your hot oil readings, they do sound abnormally high. Make sure you have the foam or rubber gasket filling in the space between the top edge of the oil cooler and the tin above it. There is a current discussion about this over in the Engine forum.

HIgh oil temperature might also be caused by a stuck oil "relief" valve, since that sucker regulates flow through the cooler.

FInally, and I have only my own anecdotal evidence to go by, I believe that painting the outsides of the pushrod tubes black does a dandy job of helping to cool the oil. In my own case, perhaps too much so, because I tend to have the opposite problem of my oil rarely getting hot enough to boil out any moisture, even living in sunny California.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

User avatar
sgkent
Addicted!
Location: Citrus Heights CA (near Sacramento)
Status: Offline

Re: EGR Question - High Oil Temps

Post by sgkent » Mon Sep 14, 2015 6:59 pm

in answer to three questions. (1) EGR would lower oil temps not raise them. It effectively lowers the amount of fuel and air that can be combined on each charge. (2) VDO made the original VW gauges. They make them for many car manufacturers, They were the standard for years until suddenly no one could tell what time it was unless they had a digital watch. I trust my VDO gauges and they do reflect what my bus engine is doing. (3) If the EGR did not work, and you had all the connections apart to be sure none were plugged or had a block off plate, then the tube inside the plenum is coked up. It fills with hard carbon. It is a tube the length of the plenum, with holes in it so the EGR gases are spread evenly thru the plenum and not just to one cylinder, effectively killing it.
TBone208 wrote: "You ppl are such windbags. Go use your crystal ball to get rich & predict something meaningful. Nobody knows what's going to happen. How are we supposed to take ppl who don't know the definition of a recession & "woman" seriously?"

Merlin The Wrench

Post Reply