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I got a 91′ accord that’s newly been rebuilt. I went to replace the oil pressure switch because it was leaking. What’s happening now is the oil light rhythmically comes on when the car is all the way warmed up and I am driving, and it will go solid red (meaning no oil pressure) when the car is stopped. When I am in park and rev the car up the light will start blinking again.
What I have done to test the connection to the switch is jack the car up, turn it on, and then unplug the switch connector. When I did it the first time, the oil light went off completely; when I did it the second time the oil light started blinking rhythmically (as though it were malfunctioning).
I was thinking maybe the switch is defective, I may just replace it. But if that won’t work maybe pressure test is in order. Thing is the engine runs fine and it did run fine even before I replaced the switch.
Either I damaged the connector when I took it off my old one, or the new switch I got is defective. OR, I really do have bad oil pressure and I have ruined my engine since I ran it with the light on for over 10 miles. This seems unlikely cause the car sounds healthy. There probably is pressure, there must be because the old one didn’t trigger the light before. This new switch is triggering the light like there’s no tomorrow.
Either way I still need some help on what to do. Eric, you would know about this since you worked on Honda’s a lot.
Ty.
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[quote=”college man” post=32910]here is a video for you.
I think i’m doomed, I hear a diesel like knocking sound from the engine after its hot… Damn.
Ah well, what can I do now? I will pressure test it to be certain its got a problem.
Don’t guess especially when it comes to oil pressure. Given that the engine was freshly rebuilt I would say the #1 suspect is the bearing clearances but you won’t be able to know this till you put an oil pressure gauge on there and check the actual pressure. They’re only $20 at Harbor Freight, I think that’s worth the investment for piece of mind. It’s also critical that you’re using the correct oil for the engine so make sure you’re running what’s listed on the oil cap.
Now that I’ve read the second page it sounds like more of what I suspected. This is the reason that I don’t recommend that you rebuild an engine as it’s not often done properly and fails shortly afterward as a result. Honda bearings are color coated to size, you can’t just slap in a set of bearings and call it good you have to measure the crank journals and the connecting rod and main bearing bores and find out what thickness bearings you need to do a proper bottom end recondition. If it’s not done correctly you get poor oil pressure and a damaged engine as a result. Engine building is a precise science, if you don’t take the time to measure everything and true up all the clearances and tolerances then it’s not likely to last very long.
[quote=”EricTheCarGuy” post=33086]Don’t guess especially when it comes to oil pressure. Given that the engine was freshly rebuilt I would say the #1 suspect is the bearing clearances but you won’t be able to know this till you put an oil pressure gauge on there and check the actual pressure. They’re only $20 at Harbor Freight, I think that’s worth the investment for piece of mind. It’s also critical that you’re using the correct oil for the engine so make sure you’re running what’s listed on the oil cap.
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Yeah bearing clearances, that’s what the people on the Honda forum were saying. I did get the pressure tester from Harbor Freight (16.99 with coupon) but haven’t used it yet because its a NPT thread instead of the Honda BPT (British Pipe Thread). But I read on a forum that you can use NPT on a BPT, is this true Eric?
I have good news though. I replaced the old pressure switch with a Beck Arnley one and it seems the oil light problem has gone away. Maybe its because the Beck Arnley says it was “MADE IN JAPAN” B)
I guess the BWD switch was not set to factory specifications.
[quote=”EricTheCarGuy” post=33086]
Now that I’ve read the second page it sounds like more of what I suspected. This is the reason that I don’t recommend that you rebuild an engine as it’s not often done properly and fails shortly afterward as a result. Honda bearings are color coated to size, you can’t just slap in a set of bearings and call it good you have to measure the crank journals and the connecting rod and main bearing bores and find out what thickness bearings you need to do a proper bottom end recondition. If it’s not done correctly you get poor oil pressure and a damaged engine as a result. Engine building is a precise science, if you don’t take the time to measure everything and true up all the clearances and tolerances then it’s not likely to last very long.[/quote]
Colored coded, I wonder why they would do that. I just figured STD would be fine since it does have STD pistons and rings in it, so why not STD bearings? So I thought but I didn’t read the manual carefully enough. I find it odd they don’t just put one size on there but have to color code it. Is it likely I have too much clearance or too little? I had the machinist measure the crankshaft and it was in spec, but it was on the loose side of tolerance.
The car runs very well though, at 500 miles it read 185 psi compression across all cylinders. Someone said 200 psi is perfect compression for a rebuild but I did my test on a cold engine and not at WOT, so it should have been higher (like 200).
[quote=”Mishakol129″ post=33339]
Yeah bearing clearances, that’s what the people on the Honda forum were saying. I did get the pressure tester from Harbor Freight (16.99 with coupon) but haven’t used it yet because its a NPT thread instead of the Honda BPT (British Pipe Thread). But I read on a forum that you can use NPT on a BPT, is this true Eric?
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No. The angles across the flanks of the threads are different, so they wouldn’t seal right and could cause damage to the threads in the block.
Plus its BSPT, British Standard Pipe Thread.I’ve just used my standard thread gauge on Honda engines if memory serves. My gauge set came with both fittings anyway, it’s strange your’s only came with 1.
As for the bearings or the bearings on ANY engine clearance is critical. That’s why when you build an engine at the VERY least you need to put plastigauge on each of the journals after torquing everything down to check the clearance and make sure it’s in spec, it’s even better if you actually measure EVERYTHING to ensure proper clearance. If not your oil pressure will suffer and it may cause engine damage. Engine building is an EXACT science NOT a guessing game or ‘good enough’ proposition. In fact I would go so far as to say that engine building is an art and getting to be a lost one from what I’m seeing.
[quote=”EricTheCarGuy” post=33404]I’ve just used my standard thread gauge on Honda engines if memory serves. My gauge set came with both fittings anyway, it’s strange your’s only came with 1.
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So you mean I can use NPT on the BPT honda block?
[quote=”EricTheCarGuy” post=33404]
As for the bearings or the bearings on ANY engine clearance is critical. That’s why when you build an engine at the VERY least you need to put plastigauge on each of the journals after torquing everything down to check the clearance and make sure it’s in spec, it’s even better if you actually measure EVERYTHING to ensure proper clearance. If not your oil pressure will suffer and it may cause engine damage. Engine building is an EXACT science NOT a guessing game or ‘good enough’ proposition. In fact I would go so far as to say that engine building is an art and getting to be a lost one from what I’m seeing.[/quote]
Yeah, I now know. Next time i’ll do it right. My question is how would you know to order the right bearings? I mean, would you get STD, OS or US (undersize)? A reputable machine shop could probably tell me.
It has to have good oil pressure though cause I had a oil pan gasket leak that was literally spraying oil out of like crazy. That BWD oil switch didn’t function right at all.
You measure the journal the bearing goes into in at least 4 places. You measure the bore that the bearing goes into needs to be measured as well, also in at least 4 places AFTER you torque it to spec. Once you have both readings subtract them from one another, then subtract the proper clearance from that number and what you have left is the bearing size needed to get you to that clearance.
Bore-Journal=x (clearance) x- ideal bearing clearance= bearing size
You’re still not done. Once you get the proper bearings and install them you need to recheck the clearance using plastiguage to see if it’s correct before final assembly.
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