after oil wrote:i missed that las post phillip, usually i get an email..
anyway...
the rad guy hooked up a device much like the one in the al's photo. it was connected to a compressor.
I'd like to know what the results to the cooling system pressure test were? If I take your suggestion from the second post you did above, you need a new head...is this the case?
Your Flaps probably equates to my "Autozone", and they won't be able to help you with a new head, but you might not necessarily need to replace the head, but you won't be able to determine that until it's been removed and checked though.
just talked to the rad guy.. y'all are right it was not a leak down test that he did. it was a pressure test.
im getting confused here. it has now been suggested to me that the pressure test al showed us in his post is to test the cooling system, up to 15 psi for leaks,into the engine . thats what the rad guy did. and that a leak down test for the engine to test for a high pressure leak, into the cooling system rather than from the cooling system is done through the injectors. (this from a parts/repair shop)
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
Careful, a cylinder leakdown test is completely different from a cooling system pressure test. He may be saying "leak down" and mean "leave pressure on cooling system for a while".
A leak down tester tests the amount of leakage in the cylinder to the crankcase, past the rings/valves, and possibly other places but it's not designed to find cylinder head gasket or head gasket leaks. It measures overall cylinder sealing wear, not specifically leaks to the cooling system.
I own a Snap-On leak-down tester setup. I don't own the cooling system pressure tester.
If the (warmed-up) cooling system will maintain pressure from an external source for a good long time and not push coolant into the cylinder, I don't think it's likely that you have a head gasket or leaking head issue. But that is only an educated guess, not a diagnosis.
I recently passed up a '77 MB 240D with a bad head gasket (or cracked head, more likely on the 240D) that exhibited very similar symptoms: rad filled, cap off, start engine, all OK for about one minute, then gasses bubbling out of rad. I would have bought it anyway, but owner wanted too much, and water on the passenger floor meant mold in the interiour.
Have you performed a cooling system leak-down test? This device attaches to the radiator where the cap resides, has a hand pump and a gauge. Pump up the pressure to 15 PSI (engine off), and watch it. Do this on a warm engine, you might find water in the oil, or a leak where you didn't expect one.
al, you called it a leak down test and a cooling system pressure test. could be why i am confused.
If the (warmed-up) cooling system will maintain pressure from an external source for a good long time and not push coolant into the cylinder, I don't think it's likely that you have a head gasket or leaking head issue. But that is only an educated guess, not a diagnosis.
if your guess is right, and i do not have a leaking head/gasket issue, then where am i?
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
There's a saying: "If you hear hoofbeats, think horses, not zebras."
Translated: when you have overheating, look for the common causes first, rather than bizarre, one-in-a-thousand occurences.
Well, it seems as if you've covered those common things. This is turning into a paper towel situation.
In order:
I would pull the water pump, inspecting the impeller. I have seen impellers rotted off entirely: no flow.
Then, with the WP off I would pull the heater hoses and rad hoses, and run a garden hose full-force through each. I have seen odd things like dish towels and wrenches in cooling systems.
After that, I'd pull the head and inspect the head gasket and sealing surface.
I'd decarbon the head and look for obvious cracks, esp. between the valve seats.
Finally, I'd pay to have the head professionally pressure checked.
asavage wrote:I need a better pic of your existing water pump before I can comment on whether the 720 version will fit. I also want a good pic of your thermostat housing.
how are you measuring temperature? The OEM sending unit appears to be disconnected:
there is a wire plugged into the sending unit. its hard to see in the photo but it comes out the right side of the unit.
a different mechanic found play in the wp pulley and diagnosed a broken pump. i got a rebulit one. it was $110.
tomorrow i am having the pump removed. and i will replace the CSD hoses too.
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
All,
Not to derail this thread, as it seems to be heading a good direction now (Thanks Al), the pics seem to show an aluminum radiator. When I put my D21 together, I bought a new 720 rad and adapted it to fit. (Check steel tube connecting lower hoses together for blockage, one reason I used 720 rad with hoses)
Back to the point, I recently rebuilt a 1990 S10 with a 2.5 four. Using the original aluminum radiator, it would build excess temps at weird times. Knowing all was fine aft of the radiator, I purchased a new one, despite all indications that the old one was "OK" (visually and water hose flow from one side to the other), problem solved.
REDNECK wrote:dude.... nissan pt# 21010-10G25, changes to 21010-10GY6 and costs $81.01 CAD. the u-hose, pt# b1069-61500 costs $18.53 CAD. all available at your local authorized dealer.
REDNECK wrote:I gave you the nissan pt#.........80 somthng bucks.......with a gasket, and still ........unbelivable man, UNBELIVABLE.
???
Are you saying that if after-oil replaces (something unidentified for CN$81.01) and a u-hose, that his problem may go away?
If that's what you meant, I didn't get it. And one or more of those numbers isn't good, I ran them through http://www.nismoparts.com/cart/?pn=21010-09W25 and they don't all come up as real numbers.
those are the numbers right off my bill from nissan, for a pump, including the supersedure, I will DOUBLE check the numbers are correct in the system at my local dealer TODAY.
I'm not saying his problem will go away, but after all this headache, and the pump was suspect in the beging,and still not removed for inspection, it seems we are all grasping.
It's a water pump...... what is he out if he pulls it off and their is nothing wrong.....a gasket and a afternoon in the yard?
I gave you the nissan pt#.........80 somthng bucks.......with a gasket, and still ........unbelivable man, UNBELIVABLE. Confused
redneck,
my nearest nissan dealer is an $80 round trip ferry ride. they always have to order my parts in from far away. i am required to prepay too. if i dont go to get the parts i pay more for shipping. i got a pump in 24 hours from FLAPS, i paid for it after i looked at it to se if its the right one.
"... the rare and elusive 1987 D21/SD25, I have come to believe these trucks exist ONLY in the minds of people who own them. " phillip R.I.P.
1987 nissan d21 SD25, canada/2 tank SVO
1993 mitsubishi delica chamonix 4X4 diesel van
