Question about Triumph Bonneville Motorcycles

1 Answer

Triumph bonneville t120 1968 low oil pressure problems.recently bought my triumph when i noticed the oil warning light did not come on when ignition was switched on.Bought a new one then it worked,but when the engine was warm the warning light flickered,the last owner said the the engine has been totally rebuilt,some one says the oil pressure should be about 20-25 psi on idle,68-80 0n start up. i used an air pressure gauge from work and it shoewd about 20 psi,now got a proper oil gauge with fitting and checking again.oil is flowing nice back into tank ok. Travelled well over 200miles so the bike seams to be riding ok. just this oil warning light. do i check the pump,if not happy with pressure reading next.

Posted by on

  • 1 more comment 
  • chrisnurney Aug 21, 2009

    Hi Charlie,
    Bought a new oil pressure switch on the net from a Triumph dealer,but before that also tried a switch from my local car spares shop and they both worked. the guy i bought the bike off said he had rebuilt the enging and done 1900 miles on it, i then drove it back upto yorkshire another 170 miles with onley small electrical problems holding me back.

  • Samuel Charles Spriggs May 11, 2010

    Could you please clarify this: "Bought a new one then it worked," A newly rebuilt engine, if done properly, should have excellent oil pressure. Oil pumps usually don't give much trouble. Was this a progessional rebuild job? Charlie

  • Anonymous Mar 22, 2014

    After i picked up my bike i noticed that i had an oil pressure warning blinking on my display... could this be a problem or is it normal? Theres no light blinking just a black oil can sign.



1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 523 Answers

Several things could be at play: Type or weight of oil, confirm this first. Not to question the rebuild but if not done properly (improper bearing clearances, too large) the oil pressure can be low and perhaps a worn pump too. While I am unfamiliar with the engine and oil pump loaction I'd check it if your able too. You'll probably need a good set of feeler gauges to check this if these clearances are outside of the pumps limits the pump will be less able to create pressure; this is of course more evident when the oil heats up.
Another cheap fix is to use a heavier weight oil.
Hope this might help,

Posted on Aug 21, 2009


1 Suggested Answer


6ya staff

  • 2 Answers


Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

1962 Triumph 3TA no oil getting into rocker arms

Probably a blockage in the oil lines. My pre-unit 6TA had a similar issue with some sludge in the oil ways.

Dec 17, 2017 | Triumph Motorcycles


Low oil pressure

If you notice low oil pressure, or oil warning light while your vehicle is running, shut down immediately to prevent costly internal engine damage, and have towed home or to a qualified technician to diagnose.
Troubleshoot Low Oil Pressure
Fixing Low Oil Pressure Light That On

on Jan 27, 2016 | Miscellaneous

1 Answer

What will cause low oil pressure gauge to enter red zone after temp is above 190*?

Odds are the engine and/or oil pump is wearing out.
A weak pump can cause low oil pressure, as can worn engine bearings.
The oil is pumped thru the crank bearings, then up to the top of the cyl heads. The pressure switch is midway up the block.
10w30 oil is made to be used between 0 degrees and 100 degrees. As the temp goes up the oil is supposed to get thicker, but only so much. So as the engine warms up the oil gets thinner and naturally looses some pressure. Thinner oil will "leak" thru worn engine parts.
You may luck out and have the pump replaced and fix the problem, but if it has more than 125,000 miles on the engine, the bearings are probably failing too.

May 25, 2016 | 1995 Pontiac Bonneville

2 Answers

What's this tiny red light that blinks when the engine is turned on? It's on Triumph bonneville t100 2012 USA model. Thanks!

Probably just lets you know you have the key in the ignition and it is switched on. However, take a look at some of these review videos.

Triumph bonneville t100 2012 USA model Bing video

Dec 27, 2015 | Triumph Motorcycles

1 Answer

What's this little red light on the right side under the big bolt that connects the handle bar to the frame? Thank you!

Hi, Hai it may be the oil pressure light I am sorry you can't find the first and best tool you ever bought for your Triumph but despair not for a mere $0 you can download another one. For more information about your issue, please visit the websites below. Good luck and have a nice day.
2012 Triumph Bonneville T100 Back to 2012 Triumph Motorcycle Model Review...
Triumph Bonneville Owners Manual Eng pdf

Btw, I’m available to help over the phone in case u need at

Dec 26, 2015 | 2012 Triumph Bonneville T100

1 Answer

2001 Triumph Triumph Bonneville Ignition switch now only works the "parking mode"

Hi, Cmelville try and take the switch apart and clean the contacts if not doable you need a new switch, for this scenario you will need your service manual, parts fiche, and owners manual if you can't find the best tool you ever bought for your Triumph, despair not, for a mere $15 you can download another one.
For more information about your issue and valuable "FREE" downloads that you will need for viewing or printing please click on the blue links below. Good luck and have a wonderful day.
Ignition switch replacement
Triumph Quit Ignoring Your Ignition Problems
Triumph Bonneville Owner Handbook Manual

Btw, I’m available to help over the phone in case u need at

Dec 14, 2017 | 2001 Triumph Triumph Bonneville

1 Answer

My bonnie just stopped...

If it stopped while the oil pressure light was may have damaged your engine. Your best path here would be to take to a dealer and have them check the bike out. Yes, I know this can be costly, but you are risking possible motor damage here, which is BIG bucks. Sorry don't have happier ideas.


Dec 07, 2009 | 2005 Triumph Bonneville T100

1 Answer

BMW 318iSE (1999) engine warning light

That sounds like you bought big problems. Oil ights indicate low oil pressure= BIG BUCKS. I would have a qualified repair shop check it out, A shop that specializes in BMW. If you are lucky, maybe the oil sender is just bad. They can also check out the Ck eng light. But the oil light is priority one.

Nov 05, 2009 | 1999 BMW 318 ti

1 Answer

Triumph Bonneville T120 oil pressure issue

The oil pressure on a new engine is:

Idle is:  20 - 25 psi
Full pressure is 68 - 80 psi.

Pressure switch operates at 7-11 psi.
The pressure switch could be faulty.

Pressure when hot may be very low
and  if it is returning oil to the tank
that is a good sign it is still pumping.

Aug 19, 2009 | 2004 Yamaha V Star Classic

3 Answers

T140 Triumph 750 Bonneville Oil Pressure

Before listening to the doom merchants try this first. Make sure the oil seal in the timing case (not points cover - the crankshaft one) is the right way round (spring side showing) and seated OK. When fitting case oil up the seal well and turn engine over (plugs out) while tapping the case home gently with your fist - if this seal is not dead right it will alow enough oil passed it to throw the pressure switch open without causing any damage. Had my T140 32 years. 

Jul 15, 2009 | 2004 Yamaha V Star Classic

Not finding what you are looking for?
Motorcycles Logo

Related Topics:

1,928 people viewed this question

Ask a Question

Usually answered in minutes!

Top Triumph Experts

Arnie Burke
Arnie Burke

Level 3 Expert

6103 Answers


Level 3 Expert

85223 Answers


Level 3 Expert

858 Answers

Are you a Triumph Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides