New Fuel Pump Leaks

[wood95ss]

From time to time we buy parts that are defective out of the box. Appears I've just been bit again. Bought a new fuel pump from OGTS mid-June and recently installed it as the existing pump (93k?) was leaking oil from the weep hole - and I hate leaks of any kind with a passion.

Noticed after the pump change my oil leak did not subside. So this morning the GT got elevated. The underside of the engine got wiped down clean (again) I let it run while I was underneath it with a drop light.

Was I surprised to see oil dribbling out of the new fuel pump weep hole about every 10 seconds with the engine at a fast idle (1200rpm) - from a brand new pump.

This happen often to any of y'all? I have all kinds of automotive/marine/aero experience but I'm just breaking cherry on the Opel GT so I'm in the learning curve big time on the strong and weak points of this German platform. Sounds like a defective pump, or have I missed something? Past experience says that with oil coming from the fuel pump weep hole is an indication of a failed pump shaft seal; when gas is discharged it's an indication of diaphragm failure.

Regardless, new pump about to go on order. Any insight? [electric cooling fan and fuel pump are looking better and better all the time].

doug

[tekenaar]

Call Gil or Dennis at OGTS and tell them your problem with the "new" FP bought from them. It's just one of the good things buying from them. They stand behind everything they sell! CALL THEM!

[wood95ss]

Intend to call them Monday and get it sorted out; not all that concerned about it. What little experience I've had with OGTS has all been good and I always hang up with warm fuzzies [rare these days].

Have ordered another fuel pump locally and it will be here tomorrow. Looking to end up with a spare fuel pump in the GT New Parts Box in the aftermath which is not a bad thing.

However the thought that is on my mind, and what I'm looking for feedback on, is about the old pump and that it was replaced because it was spitting oil out the weep hole. The new pump is spitting oil out the weep hole. Is this common to Opel mechanical pumps? - or is it just my pure dumb luck?

[oldopelguy]

Oil leaking from that weep hole tends to be one of the first signs of pressure building up in the crankcase. That means either the blow-by gasses aren't being removed quickly enough via the valve cover vent lines, either due to a problem with them or too much flow for them due to a worn motor. Not that this is always the case, sometimes the internal seal on the pump does just fail, but every time I've had the problem it has been symptomatic of a bigger issue.

[wood95ss]

Further searching references some type of filter/screen inside the valve cover that blowby gases egressing the cover must pass through? I'm guessing it's toast. Explains why there is little change in the flow of gas with/without the valve cover cap in place.

She's tired and an overhaul is in the near future after some homework and improvement in my GT learning curve. In the meantime, will the valve cover come off cleanly without disassembly of other items? I will probably break out the wrenches after writing this and find out. Gotta get in there and open up the flow path. Anything to reduce crankcase pressure and keep the oil inside the engine.

[Scott McDonald]

When you replaced the fuel pump, did you place/replace the spacer (fuel pump-to-block)? If not, I believe that can make an otherwise good pump prematurely fail.

[wood95ss]

A new spacer block and gaskets went in with the new pump.

Crankcase is well ventilated now. Removed the gauze from the vent cavities in the top of the valve cover and the path is now open. Little hole is plugged (before I got it) and the large hole is connected to the carb filter base. Fuel pump still leaks oil. Have just removed it and the weep hole cavity was full of oil.

Attacked the pump that came on the car. Broke it down to see how the pushrod is sealed. Now that I know how it is put together my only thought was to pre-oil the pushrod to get the seal wet so as not to intially stoke the rod dry at inital startup and possibly hurt it, and installed another new pump.

If this sucker leaks I'm at a loss other than to install an electric pump and regulator and block off the mechanical pump pad as thou shall not continue staining the driveway(s) and undercoating the car.

Where's the best place to mount an electric pump in the back of a GT? Options appear slim.

[GTJIM]

The oil that coats the underside of the car does slow down rust .........

[pvcar]

yah the best place for almost any electric fuel pump would be closest to the tank, i.e. somewhere above the rear axle or wheel well kind of area, there is a couple pics on this site of diffrent places.

[wood95ss]

New mechanical pump went on. Below 3,500rpm shifts and drive on secondary roads of about 30 miles netted one drop of oil dangling from the edge of the pump with no evidence of oil blown aft.

Next day the acid test - out to the Interstate. 5,000 rpm shifts and 70/75mph for about 8 miles, then a low speed run back to the house. Inspection: oil everywhere.

The ONLY thing I can contribute this to is crankcase pressure. As I've not been into an Opel engine yet I don't know if I'm missing something - as in what goes on in the area of the fuel pump drive that could be a contributing factor (blocked drain back hole? - doubtful as the area under the valve cover is as clean as the Day One). Enough of this Happy Hotel Sierra. Start fab'ing a block off plate this evening.

About to pick up a solid state type fuel pump [7 psi, 25 gph] as I'm not looking for a performance or high dollar motor driven unit. This will push fuel to a Holley pressure regulator and pressure gauge.

I'll fab up a shock/isolator mount for the pump and find a spot back by the tank to mount it and the regulator and gauge will go on the left side of the engine compartment.

New parts arrived. Center joint rubber is next.

doug

[tekenaar]

Originally Posted by wood95ss New mechanical pump went on. Below 3,500rpm shifts and drive on secondary roads of about 30 miles netted one drop of oil dangling from the edge of the pump with no evidence of oil blown aft. Next day the acid test - out to the Interstate. 5,000 rpm shifts and 70/75mph for about 8 miles, then a low speed run back to the house. Inspection: oil everywhere. The ONLY thing I can contribute this to is crankcase pressure. As I've not been into an Opel engine yet I don't know if I'm missing something - as in what goes on in the area of the fuel pump drive that could be a contributing factor (blocked drain back hole? - doubtful as the area under the valve cover is as clean as the Day One). Enough of this Happy Hotel Sierra. Start fab'ing a block off plate this evening. About to pick up a solid state type fuel pump [7 psi, 25 gph] as I'm not looking for a performance or high dollar motor driven unit. This will push fuel to a Holley pressure regulator and pressure gauge. I'll fab up a shock/isolator mount for the pump and find a spot back by the tank to mount it and the regulator and gauge will go on the left side of the engine compartment. New parts arrived. Center joint rubber is next. doug

I'd say Correct analysis, as indicated by greater oil leak at higher RPM (less bleed-off of excess crankcase pressure . . . has to go somewhere).

Small suggestion: Solex, Weber and DellOrto carbs operate best at no more than ~3.5 psi pressure, so set your regulator accordingly.

[wood95ss]

One other thought/question: Could this be a result of high oil pressure?

Historically, this engine has had 'pegged' oil pressure from day one. Once up to operating temperature oil pressure at 800-1000rpm idle is about 10 psi. Tap the gas and the oil pressure needle jumps. By 1500-2000rpm its reading 50psi with the needle pegged.

My father just brought this up to me. I've tossed it around in my head saying 'nah..no way' but again, not knowing the opel 1.9 engine and with you guys having all the experience the dumb question is the one NOT asked.

Could there possibly be an association to high oil pressure causing 2 new fuel pumps to spit oil? (flooding the mounting flange, poor oil drainback, anything? - dying to dive into this engine for the rebuild but have much reading here to do first)

[tekenaar]

Originally Posted by wood95ss One other thought/question: Could this be a result of high oil pressure? Historically, this engine has had 'pegged' oil pressure from day one. Once up to operating temperature oil pressure at 800-1000rpm idle is about 10 psi. Tap the gas and the oil pressure needle jumps. By 1500-2000rpm its reading 50psi with the needle pegged. My father just brought this up to me. I've tossed it around in my head saying 'nah..no way' but again, not knowing the opel 1.9 engine and with you guys having all the experience the dumb question is the one NOT asked. Could there possibly be an association to high oil pressure causing 2 new fuel pumps to spit oil? (flooding the mounting flange, poor oil drainback, anything? - dying to dive into this engine for the rebuild but have much reading here to do first)

Have you verified your pressure with a mechanical gauge? Is this late (regulator in OP cover) or early pump (regulator in timing cover right side)? If late OP, regulator nut facing rear?

[greensmurf20]

you say your guage pegged out at 50 pounds, so i'm assuming you think each bar is 10 pounds...

each bar is 14.7 PSI oil pressure so your running even more oil pressure than you had origionally thought. so if you peg the guage your doing about 75PSI.

[Dmcbrass]

If your oil guage is pegged you have at least 70 PSI. Thats way to much for the 1.9L engine. It sounds to me like you have the wrong oil pump cover. The early 1.9's controlled oil pressure through a relief in the timing chain area. The later ones used a relief in the oil pump cover. If you have a late model engine and an early model oil pump cover, or the oil pump cover is installed backwards (not usually possible because it will hit the chassis), you will run too much oil pressure. The early oil pump covers just looked like a cover plate from the outside. The oil relief mechanism is obvious on the later covers. A later model cover with the oil relief and gasket can be purchased from OGTS for approximately $35.

[wood95ss]

If I'm understanding this correctly, the oil pressure gauge reading of 50 is actually 5.0, which is 5 x 14.7 = 73.5psi? Holey Moley.

If I can get a couple digital thumbnails of the oil pump assembly posted here this afternoon, would one of y'all identify it for me?

Next question is the thread of the oil pressure sensor on the right side of the engine block. Let me guess: metric? My luck hasn't been good enough lately for it to be NPT. Sure would like to tap into it with a mechanical gauge while I'm waiting for parts if this is in my future to get the oil pressure back into the ball park.

[tekenaar]

Originally Posted by Dmcbrass If your oil guage is pegged you have at least 70 PSI. Thats way to much for the 1.9L engine. It sounds to me like you have the wrong oil pump cover. The early 1.9's controlled oil pressure through a relief in the timing chain area. The later ones used a relief in the oil pump cover. If you have a late model engine and an early model oil pump cover, or the oil pump cover is installed backwards (not usually possible because it will hit the chassis), you will run too much oil pressure. The early oil pump covers just looked like a cover plate from the outside. The oil relief mechanism is obvious on the later covers. A later model cover with the oil relief and gasket can be purchased from OGTS for approximately $35.

Good idea, but if switching from early OP cover (flat) and early timing cover, make sure you block (with VERY stiff spring) original regulator in right side of timing cover, else both regulators are in oil path. :o

Just a thought, if you have late timing cover (OP regulator blocked) and early (flat, no regulator) OP cover, you have NO pressure relief (regulation) at all . . . very high oil pressure.

[wood95ss]

Here's the oil pump and timing cover. Assume this is the later version mentioned above.

Past experience is high oil pressure = stuck relief spring, or too stout.

I see there is a pipe plug next to a bung on the left side of the timing cover. Can this be tapped into for a direct read gauge?

[tekenaar]

Originally Posted by wood95ss Here's the oil pump and timing cover. Assume this is the later version mentioned above. Past experience is high oil pressure = stuck relief spring, or too stout. I see there is a pipe plug next to a bung on the left side of the timing cover. Can this be tapped into for a direct read gauge?

Pipe plug is M14x1.5. A brass adapter to 1/8"NPT (most common thread for gauges) is available from eGauges.com under P/N R7963 or you can use a 1/4"x18NPT (threads and diameter are nearly the same as M14x1.5) brass reducer to 1/8"NPT, as suggested by R-Bob in another thread.

Word of caution on using the second option NPT reducer, R-Bob's suggestion was for replacement of OP sender which screws into cast iron block. I personally don't feel completely "safe" doing it in cast aluminum, as you would do here. Better to go with the "correct" adapter from eGauges.com.

[Dmcbrass]

That looks like a late model oil pump cover, so my theory is wrong. I would definately check the pressure mechanically. Also remember that if there is a bad connection on the oil sending unit wire, the guage will read low. Wire disconnected = pegged pressure guage.

[wood95ss]

Problem Solved!

Removed the pressure relief spring and piston to check them out and reinstalled them. All looked fine. Fired her up and oil pressure gauge pegged.

Looonnng time ago my father changed the oil pump base plate and saved the old one. I asked why the change and he couldn't remember the reason. So I dug out the old plate and it too was the later version. Removed the relief valve. Spring in this cavity was considerably weaker than the one I just removed from the pump on the car so I installed this weaker spring and piston.

Cold oil pressure at idle gauge indicates 40. With 'some' temp in the oil, at idle, pressure indicates 10. Needle never exceeds 40 now. Casually took the car around our 3 mile block (45mph) and stopped to inspect. Fuel pump and everything around it dry. Drove the circuit one more time with a lot more rpm (5k) and parked it. Fuel pump and surroundings dry. No more oil leak at the fuel pump.

Thnx for the specs on the pressure sending unit thread size.

[Dmcbrass]

I'm curious what oil pressure readings your GT's run. Mine runs:
3.7 @ 2000 RPM and above at normal engine temperature
2.5 @ Idle at normal engine temperature
I have the late model oil pump cover, (pressure relief in the cover)

[wood95ss]

From what I could see this evening out on the interstate between 3,500 and 4,000 rpm it was 3.5 - 4.0. Idling indicates 1.0 and rock steady.

The removed spring (the stout one) had what appeared to be tan or flesh tone paint on it as some type of identifier. I wonder if this spring belongs in the timing cover relief valve bore and somehow made its way into this pump decades ago.

Engine without doubt is not working as hard as it was. Gained a pony or two. Wonder how much oil pressure the engine was getting at 5,000 rpm?

[GTJIM]

With the relief valves jammed shut - or not there (using front cover and pump cover together, without either relief valve) - the gear pump used for pumping the oil can reach pressures up to 1,500 psi - or 100 bar

Enough to blow the oil filter off and/or remove the press in oil gallery plugs .......

[tekenaar]

Originally Posted by wood95ss Problem Solved! Removed the pressure relief spring and piston to check them out and reinstalled them. All looked fine. Fired her up and oil pressure gauge pegged. Looonnng time ago my father changed the oil pump base plate and saved the old one. I asked why the change and he couldn't remember the reason. So I dug out the old plate and it too was the later version. Removed the relief valve. Spring in this cavity was considerably weaker than the one I just removed from the pump on the car so I installed this weaker spring and piston. Cold oil pressure at idle gauge indicates 40. With 'some' temp in the oil, at idle, pressure indicates 10. Needle never exceeds 40 now. Casually took the car around our 3 mile block (45mph) and stopped to inspect. Fuel pump and everything around it dry. Drove the circuit one more time with a lot more rpm (5k) and parked it. Fuel pump and surroundings dry. No more oil leak at the fuel pump. Thnx for the specs on the pressure sending unit thread size.

If you're talking about marks on your OP gauge, each mark on the OP gauge is actually about 15psi (BAR = 14.6), so 4 BAR is about 58psi.

Looks like somehow the "TC regulator bypass spring" ended up in your OP cover regulator, but your OP mystery is solved and that's the important thing.