Oil pressure problems : V-Twin Forum: Harley Davidson Forums

roaddawg65 · 03-21-2010, 05:23 PM

Just the 30,000 mile service on my 07 FLHTC. Started it up to check for lead and such and everything was fine. After finishing I took it for a ride. About a mile and a half from home the oil pressure dropped to zero and the light came on. I put the bike on the trailer and hauled it home. Since than I checked the light and gauge and both were fine. The oil sending unit showed bad so I replace it and nothing changed. I then checked the pressure with a manual gauge and got nothing. Now it say to let the engine warm to normal operating temp. with I didn't do. If you have no oil pressure and run the engine what is going to happen. A friend suggested it could be a blocked oil filter which I have consider too. Has anyone had any problems with K&N filters. In the past all I have used are Harley and Amsoil. Need to try a few things before I tear into the engine.

blkfalc4 · 03-21-2010, 05:49 PM

From pickup port to feed side of oil pump it goes thru bypass valve, (maybe stuck open), from there to oil psi sender on it's way to filter. So filter shouldn't be problem.
Sending unit is on feed side of filter, not after. Pull sending unit and should have plenty of oil out the port. If not, bypass valve or oil pump problem.

Going on plenty of oil in tank.

claydbal · 03-21-2010, 06:13 PM

plenty oil in tank

thats what i was thinkin. a mile after service, and no oil pressure?

blkfalc4 · 03-21-2010, 08:06 PM

Quote:

Originally Posted by claydbal

plenty oil in tank

thats what i was thinkin. a mile after service, and no oil pressure?

Wasn't there someone on here that had a receipt in the tank that clogged the pickup line? Caused all kinds of problems.

But anyways, oil in tank, pickup line clear, oil to pump, from pump to bypass valve, out to psi sender/oil filter, filter to engine.

No oil at sender, backtrack.

hdmikeyb · 03-21-2010, 08:50 PM

Quote:

Originally Posted by roaddawg65

Just the 30,000 mile service on my 07 FLHTC. Started it up to check for lead and such and everything was fine. After finishing I took it for a ride. About a mile and a half from home the oil pressure dropped to zero and the light came on. I put the bike on the trailer and hauled it home. Since than I checked the light and gauge and both were fine. The oil sending unit showed bad so I replace it and nothing changed. I then checked the pressure with a manual gauge and got nothing. Now it say to let the engine warm to normal operating temp. with I didn't do. If you have no oil pressure and run the engine what is going to happen. A friend suggested it could be a blocked oil filter which I have consider too. Has anyone had any problems with K&N filters. In the past all I have used are Harley and Amsoil. Need to try a few things before I tear into the engine.

After doing your checks and not finding anything you can try back feeding oil into the oil passages. Take a suction gun and fill with engine oil. Adapt a fitting to the engine from the suction gun and feed oil back into the engine. Might be a good idea to pull the filter to block the port there so that the oil you force in backfeeds and hopefully clears any obstructions. Worth a try.

roaddawg65 · 03-23-2010, 05:10 PM

thanks for the info, am still waiting for my friend who is a master mechanic to get back to me I will post what we find.

roaddawg65 · 03-25-2010, 11:17 AM

Well I'm off the first page so not much chance of anyone seeing this but here it goes. Check the valve and it seems to be ok. Book says it should measure 2.25" from the edge of the cam plate to the valve, mine was 2.125". Took the valve out and it looks fine. Measured the distance to the seat and it was 2.25" so allowing for the thickness of the valve it should be good. Looks like I check the pump next.

46u · 03-25-2010, 03:41 PM

Very interested on what you find out. I was going to suggest checking the pressure valve till I read your last post.

n7ki · 03-26-2010, 08:45 AM

Seems like it would be obvious to check the sending unit for the oil pressure.

head · 03-26-2010, 08:51 AM

i think he mentioned that he already replaced the sendng unit.

head

46u · 03-26-2010, 09:18 AM

Quote:

Originally Posted by n7ki

Seems like it would be obvious to check the sending unit for the oil pressure.

Yes in his original post he said he replaced the sending unit and even checked the pressure with a external test gauge like in the manual and did not have any pressure.

Then he checked the pressure valve in the cam plate and is going to check the oil pump which is about all he has left to check.

roaddawg65 · 04-02-2010, 03:33 PM

In case anyone is still interested, here it goes. Pump was ok did replace the sending unit but the problem was me or my need to have everything clean. I had missed place my oil funnel and used a different one so I cleaned it very good using those blue paper shop towels. Do not use them, use real cloth ones!!! I found a piece of one in the oil passage just above the relief valve when I took the cam plate and pump out, MY BAD!!! Put it all back together with new chain tensioners, relief valve and spring. Had 50psi of oil pressure to start and now it is fluxuating. I think I need to back in and check the valve as it would seem that it is not working right. Used an aftermarket spring from Feuling. Or it could be that along with the sending unit going again but the light works fine. Will have to get with my local experts for a skull session with me providing the drinks.

46u · 04-02-2010, 05:02 PM

Glade you got it fixed and I use the blue paper shop towels all the time but if I wipe a funnel out I all ways look in it before putting oil thought it to make sure it is clean. You know the little plastic seals in the cap on the bottles oil come in. Had a guy change his oil and the seal must of stuck to the top of the bottle instead of the cap and he did not notice it. Brought the bike to me because of no oil pressure and the seal was covering the feed hole. So when putting oil in ALWAYS check the seal.

Do not feel bad. One time I had a guy come to my shop and said he took the oil tank off to have it painted this was years ago and he had a shovelhead. Said he put it back on and the dipstick keeps blowing out of the tank. First thing I checked was to make sure he had all the lines hooked up to the proper fitting, which he did. So this told me there had to be a blockage in the vent line. Come to find out when he had the tank at the painter he plugged the lines with tops off ink pens and forgot to take the one out of the vent line which made the tank build up pressure and blow the dip stick out.

I have had people come to me and tell me there bike quite running and I look in the gas tank and it did not have any gas. This happen MORE then a couple of times. Had one guy I built and engine for. He picked it up just before a long holiday weekend. He came in to the shop cussing me after the long weekend that his motorcycle quite ruining the day he picked it up and road with it in the back of his truck all weekend looking for me. It fell over in the truck and messed up the gas tank and not only wanted me to fix the bike but pay to have the tank fixed. I took the gas cap off put gas in it and it fired right up.

I could go on and on with things I have seen.

Z-Man747200 · 04-02-2010, 05:07 PM

Great thread. Thanks for all the info!

RG50 · 04-02-2010, 06:44 PM

Those blue towels suck,they just fall apart like you said.
I buy the red shop towels.
I also clean the funnels out with brake/parts cleaner before each use.