1971 transporter, possible overheating, could use some advice...

[skills@eurocarsplus]

have you put a real mechanical gauge on this?

those VDO gauges suck ass, and the dual pole senders trigger the light at a higher pressure ( I think stock vw is 4-5 psi, the VDO is closer to 8-10 PSI)

I don't think I would string the builder by the balls....

how does the pump fit? if it is NOT tight, you WILL have problems. I have had to have pumps o-ringed to fit snug in the case. if you were able to simply shimmy that pump out, it's too small for the bore. a proper pump fit WILL require the puller, and possibly taking some torque off of the case nuts to remove it
_________________

[hylomatt]

@skills, I haven't received the new pump yet. I get it on tuesday. I paid for 3-day shipping but didn't see the info about how long it takes to get the item out of the door. I had planned on doing the work this Friday or Saturday but oh well. Instead, I'll weld in my new, center heating pipe

Also, I've only put a hand-held mechanical oil pressure guage on it but I didn't test long enough to reach these points of heat and low pressure. I'll need to redo that test and give it more than 10 mins.

[skills@eurocarsplus]

I was asking about the pump fitment of your current pump...if it was loose, chances are the new one will be as well
_________________

[SGKent]

[hylomatt]

I spoke with my engine builder today and he said that a 26 mm pump was never stock and that a 21 mm pump was the correct one to be using. And then, of course, I've heard and read conflicting information here.

Found this in another thread:
21mm for 1500 single relief
26mm for 1600 dual relief

I know we've already gone over this but with the builder emphatically stating that 26 mm is a heavy-duty pump and not the stock size I wanted to ask again.

[Amskeptic]

[hylomatt]

Okay I'll have some feedback for you soon. I just got the pump in last night and reassembled this morning but I had to break for work. I have been doing a little driving with the adjusted Springs and the 20 50 weight oil and the pressure while driving is correct now so the spring adjustments and the thicker oil to combat the smaller oil pump have been a good patch for any time but idle.

[blue72beetle]

[hylomatt]

I'm getting really good at disassembling this much of the engine! And of course I didn't look for problems as closely as I could have. Damn. Ok, I guess it's coming apart again.

[airschooled]

[blue72beetle]

Where do new cases come from now?
_________________
-Andy-
-1970 Ghia-
-1971 Bus 1776 Microsquirt EFI-

[hylomatt]

Mine says Brazil on the side of it

[skills@eurocarsplus]

you never did answer my question, and if you did, I missed it.

how tight is the pump in the bore? it should be a mofo to remove and need a rubber mallet to get back in there.

if it slid right it, it's wrong
_________________

[hylomatt]

@skills, sorry about that, I never did answer your question but I only just removed it this weekend so I had forgotten you asked. The pump that I removed was wedged in well enough to begin bending my puller until I loosened the case nuts above and below the pump. Once the case nuts were loosened, the puller was able to do its job.

Same thing for the new one as well. It's quite snug unless I loosen the case nuts.

[aeromech]

Are T4 oil pumps just as tight? My experience is no
_________________
Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound

[hylomatt]

Well I'm going to take it apart again just to check all the stuffs. Tang engagement is at its minimum so I'll adjust that. And endplay is .006 maybe .007 which is good and within spec. I'll check the oil gallies as well for line up with the new pump.

[skills@eurocarsplus]

[aeromech]

[SGKent]

re T4 pumps - the NOS one in my case was loose by .0005" or so. All the 10 to 15 pumps I had were the same to the 4th digit and both cases I measured were the same to 4th digit. All the specs were within the published Bentley. There is some overlap in Bentley meaning a case can be perfect in size, and the pump be perfect in size, and the two be slightly loose by .0005" to .001"or so. Funny thing is that over time varnish etc build up and the clearance goes away. Some folks break the ears off trying to get them out.

Bore for the oil pump housing is .03 mm (.00118") variance (2.7559" to 2.7570".
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[hylomatt]

Okay so it's update time. This weekend I pulled the engine out and did some checking, etc.. I retorqued the case and the heads. The case had a few loose nuts and the heads definitely needed retorquing. I checked the oil pump for how well it matches the case oil galleys. It's not perfect but it was really close. I made an adjustment on the drive gear to ensure the tooth was fitted into the camshaft slot properly. Then I measured the end play on the pump which is now .06mm.

I also used a good Permatex product to fill all unnecessary holes in the fan shroud and air gaps around the driver side elbow which had been reoriented for air conditioning way back when. In the process, I found what I believed to be a leaking oil cooler with no foam around it. So I purchased a new oil cooler and added an additional strip of expanding foam. I also found a broken Hoover bit when I pulled the engine so a lot of those things weren't helping me maintain temperature. So a new oil cooler, a Hoover bit and a new seal kit for any seals that I had to break while I was doing all this work.

After disabling the coil to distributor connection and priming the oil ways I then let the vehicle warm up for a little bit and took a short 20-30 minute test drive. The temperature was looking pretty good and the pressure was a little lower than what I expected around the end of the test drive. At ~3,100 RPM I had ~25 psi oil pressure at just a hair under 200 F. I had also switched back to 10w30 oil.

So, I'm going to try straight 30 weight oil. I heard a little bit of clicking in the passenger side valve cover so I probably misadjusted one of the valves and I need to reset the accelerator cable tension because I set it a little tight. I'll go ahead and dump the oil and go around and do another tune-up probably tomorrow night.

I'm not certain if I should fight for that extra 5 to 6 PSI. I need to give it a good highway test and see if that oil light ever flickers. I have currently gone back to using a T-fitting with the original pressure sensor and the vdo sender.