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Engine Specific Info and Questions => IDI Engine => Topic started by: ein bora on January 13, 2009, 11:02:01 am
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I'm going to be installing a mechanical oil pressure gauge on my 1.9 IDI, which of the two oil sensors would be the best place to tap in to? Also should I use a splitter and also keep the original electric sensor too??
Any thoughts appreciated. Thanks.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Yeah, that's best. If you didn't want a "T", you could pull the filter flange and drill / tap another boss for your line.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Yes - I was thinking the same. As to the t-fitting, I'm assuming that the thread on the 1.9 will be metric, the fitting that comes with the gauge will be standard - is there a metric fitting that will accommodate the gauges fittings?? Or how would I do this??
Any help - thanks.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Yeah, that's best. If you didn't want a "T", you could pull the filter flange and drill / tap another boss for your line.
Hummm....that would work re the metric/standard thread issue.
Thanks.
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Yes - I was thinking the same. As to the t-fitting, I'm assuming that the thread on the 1.9 will be metric, the fitting that comes with the gauge will be standard - is there a metric fitting that will accommodate the gauges fittings?? Or how would I do this??
Any help - thanks.
The stock sensors are M10x1... as luck would have it, very very close to the 27NPT (iirc) that many standard NA aftermarket gauge will likely come with.... the oil pressure kit from NAPA, for instance.
I usually use electric gauges and sensors, but on the odd time when I use a mechanical gauge (first engine startup, etc) I've had no problems with the 27NPT fitting, particularly with a few turns of Teflon tape. YMMV, of course!
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pull the stock sender out and buy a brass T fittin but tap the bittom to an M*10 thred and tighten that in where the stock sender went. put the after market guage on one side of the T fitting and the stock sender on the other side(just so it doesnt beep at u)
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Yeah, that's best. If you didn't want a "T", you could pull the filter flange and drill / tap another boss for your line.
I've been wondering about the same thing.
I'm going to be putting in an oil pressure gauge when I put the new engine in soon, 1.6 T/D and have been wondering the same thing. My N/A engines sensor for the light is in the head, the T/D has one in the outlet flange along with the turbo oil line. I'm gonna keep them both but how much difference in pressure is there between a flange and a head reading. I'm just thinking that the head is the last place in the system to get oil and you want to make sure there is enough pressure left at that point but I never used an actual gauge in one of these engines and don't know what the actual pressure differential is between the 2 locations or what the should show.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Yeah, that's best. If you didn't want a "T", you could pull the filter flange and drill / tap another boss for your line.
I've been wondering about the same thing.
I'm going to be putting in an oil pressure gauge when I put the new engine in soon, 1.6 T/D and have been wondering the same thing. My N/A engines sensor for the light is in the head, the T/D has one in the outlet flange along with the turbo oil line. I'm gonna keep them both but how much difference in pressure is there between a flange and a head reading. I'm just thinking that the head is the last place in the system to get oil and you want to make sure there is enough pressure left at that point but I never used an actual gauge in one of these engines and don't know what the actual pressure differential is between the 2 locations or what the should show.
I'll second this comment.
Why in the world would you want to read your oil pressure BEFORE it goes to anything?
When reading at the head your reading the pressure AFTER it goes through all the other bearings. If you have good pressure here everything before it will be good.
If your reading it ant he filter mount your reading the pressure out of the pump, cool and all but I believe your being mislead by this reading.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Explanation please?
I've been wrong before and I'm sure I will be again but I think your off base here. If I'm off I would like to know about it so I'll stop giving out bad info.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Why in the world would you want to read your oil pressure BEFORE it goes to anything?
When reading at the head your reading the pressure AFTER it goes through all the other bearings. If you have good pressure here everything before it will be good.[/b]
If your reading it ant he filter mount your reading the pressure out of the pump, cool and all but I believe your being mislead by this reading.
To an extent, its all relative, isn't it? What I mean is at the filter will be the highest reading. Lets say 50 psi is normal at that location. If it is lower, you'll be concerned. For the head, it is the lowest pressure in the system. So, lets say 25 psi is normal on your engine there. If it is lower, you'll be concerned. Right ? The absolute pressure is not what you are concerned about, but rather that the bearing are all seeing their normal flow of oil.
That said, I went with the filter boss as the head's absolute pressure is not accurate because it is down stream from many bearings that have oil supply openings on the crank. These open and close many times a second, so the pressure will be fluctuation many times a second. If you had a transducer connection to a scope, you'd see it.
Secondly, what are the failure modes ? No oil, blocked filter, open bypass valve, blocked passages, blown bearing, broken passage, blown gasket. For each and every one of these you'll see abnormal readings ( high or low) at either sample location. Right ?
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I agree sorta still have a concern.
Yes if said engine is running 25psi at the head and anything different may indicate a problem but if you are it reading at the filter mount I don't think you would see a bad cam tower for instance
Now if your reading at the head you will as well as seeing a main bearing, IM shaft bearing, rod bearing issues.
So far I'm not convinced the filter is the place to read it. I'm sticking with the head untill someone convinces me otherwise.
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I agree sorta still have a concern.
Yes if said engine is running 25psi at the head and anything different may indicate a problem but if you are it reading at the filter mount I don't think you would see a bad cam tower for instance
Now if your reading at the head you will as well as seeing a main bearing, IM shaft bearing, rod bearing issues.
So far I'm not convinced the filter is the place to read it. I'm sticking with the head untill someone convinces me otherwise.
I think you would see it at the filter (Post filter - as in the pressure the very first bearing sees.) Here's why - Blown cam tower = more flow = drop in pressure seen at the filter exit. Blocked Cam Tower passage = increased reading at the filter exit.
The VW engineers must have had a similar thought as they put their gauge sensor at the filter exit and the warning light sensor at the head.
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i think the 1.9 has an extra port that you can unscrew and install your sender. if not then you will have to install a T fitting.
best spot is the filter flange. the side of the head won't give you the actual oil pressure.
Explanation please?
I've been wrong before and I'm sure I will be again but I think your off base here. If I'm off I would like to know about it so I'll stop giving out bad info.
explanation of what?
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best spot is the filter flange. the side of the head won't give you the actual oil pressure.
There ya go.
I'm looking for an explanation on this comment.
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I had a temp gauge sender in the spot at the oil filter and it restricted the flow to too low a pressure and i got the buzzing in the dash from the pressure sender in the head. I had to relocate it to the top of the head (swap the pressure sender for the temp sender).
Just a side note.
effin sick avatar btw.
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I think you would see it at the filter (Post filter - as in the pressure the very first bearing sees.) Here's why - Blown cam tower = more flow = drop in pressure seen at the filter exit. Blocked Cam Tower passage = increased reading at the filter exit.
The VW engineers must have had a similar thought as they put their gauge sensor at the filter exit and the warning light sensor at the head.
I suppose.
I have considered moving my gauge down there just to see but hell I get 80+ psi at the head when I fire it up. Wonder whats down there? I don't think I want to know.
just for kicks though if I get home before dark tonight I'll see about moving it down just for reference.
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I am with you zukgod on the location. On all the SBCs we put together for circle track racing we always went with at least one sensor in the head as it is last to get oiled. It will also be the first to loose it if say your clutch explodes and pieces of it fly through the oil filter and cause it to leak. Yes that happend and when you are making 100 psi at the filter it takes awhile for it to show off of the filter base. We had 2 oil psi gauges and the one at the filter was still showing 20 psi when the head had nothing and was shut down.
FWIW Any guage is better than nothing and at least you'll have a reference point to go from. I liked the 2 gauges in the race car, but eventually you'll end up with 20 gauges to watch and still be trying to drive so it isn't practical in a car for the street. My .02
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Sorry if this sounds stupid, but what if you took a line off of both spots and ran them into a "T" and then to a single gauge, wouldn't you then get a balanced reading??
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the pressure out of the filter mount would overpower the head reading.
Not to sure what you would see on the gauge.
The line would charge the oil galleys in the head so I doubt it would be a bad thing really.
Hmm, there are always other ideas out there it seems.
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Sorry if this sounds stupid, but what if you took a line off of both spots and ran them into a "T" and then to a single gauge, wouldn't you then get a balanced reading??
Interesting idea. For aircraft with dry sumps, some of the engines have multiple oil lines from the supply pump. Would be interesting. Might even help the cam last longer.
I agreee with zukgod1 - I don't think it would harm anything :-)
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Yet another angle fwiw:
Being an electrical engineer I like to solve these mysteries of the universe with wires and solder and stuff... one gauge, one switch, a sensor at the head *and* a sensor at the flange:
(http://i197.photobucket.com/albums/aa85/vwaldon/tri-cluster.jpg)
The switch spends 99+ % of the time watching the flange sensor. Why? Because that's the only spot that VW publishes what the pressure *should* be, and I've retained the pressure warning switches at both locations so I'll know if I lose pressure at the head via a different system.
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If you have electrical gauges that's the shiz right there but those of us that have mechanical gauges are kinda limited.
I don't have a Bentley here Vince what does VW say the pressure needs to be?
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I don't have a Bentley here Vince what does VW say the pressure needs to be?
Minimum 2 bar at 2000 RPM at the flange, engine at operating temperature (rad fan has cycled once).
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I have that at my head, bet that means I'm good :)
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I have that at my head, bet that means I'm good :)
Yeah, you should be golden. But, this is just an indicator. The exact pressure is less important as the trends. There are electronic engine monitors in small planes that watch trends and give you warnings if things change. Aircraft Spruce sells them.
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And I suspect there is a reason we dont have them on our cars.
Not needed when your not flying at 10000ft.
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Not needed when your not flying at 10000ft.
Dunno 'bout you guys, but I definately fly.... ;-)
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Dunno 'bout you guys, but I definately fly.... ;-)
For some reason I have no doubt!
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best spot is the filter flange. the side of the head won't give you the actual oil pressure.
There ya go.
I'm looking for an explanation on this comment.
so my statement is correct, but if you would want to put a gauge at the side of the head, it wouldn't be a bad idea. Zero pressure from the head could indicate a problem (obviously). the actual oil pressure will be found at the flange where it indicates in the manual.
as for increasing pressure, would this (http://www.jbugs.com/store/merchant.mvc?Screen=PROD&Product_Code=9202&Category_Code=) kit work on a vw??? my hot idle oil pressure at the filter flange is about 15 psi. and it must be at least 25 psi @ 2k pm, but no way to confirm rpm's (yet) - all this is due to my bypass filter being installed. i figure if i just 'modify' the oil pump that it can supply the extra bit of oil pressure required and everything will be normal. surely someone has fooled around with these pumps to increase pressure like the big block V8 guys?
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I haven't checked my psi at the filter but at the head @ 3000rpm I'm getting 38-42 depending on the temp.
Last time it was apart I took the relief valve apart and added a stiffer spring, problem is I add new main/ rod bearings (again) at the same time so I cant tell ya if I actually received an increase in pressure.
I'm also running a bypass system that I built, pulls off the second port back on the flange and returns to the plate on the front of the engine.
I used a brass nipple about 2" long and silflossed one end shut then drilled a small hole to regulate flow. My first hole was 1/8" and that was way to large so I re-welded it up and drilled a smaller hole, cant remember at the moment exactly what size :(
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as for increasing pressure, would this (http://www.jbugs.com/store/merchant.mvc?Screen=PROD&Product_Code=9202&Category_Code=) kit work on a vw???
It is possible to have too much oil pressure. You'll wash away your crank bearings. In the early 1980's one of my first jobs was at Federal Mogul's research lab in Ann Arbor. I did tests on bearings where we simulated too much oil pressure. The test would eat through the bearing material to the steel backing plate in a few days. It was called "Capillary erosion".
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what pressures where you running to get that result?
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what pressures where you running to get that result?
LOL ! I knew that was an obvious question. I do not recall what the pressure was. Thinking about the test machine, it was nothing out of sight. Since our mechanical gauges top out at 100 psi, I would imagine you would not want pressure near that level.
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Well that probably doesn't cross over to our cars then.
In stock form we get 100 psi on start up and run 60 psi consistently so...