All of a sudden my 99 Series 1 is sounding like a diesel. Don't know if this is valve chatter or what. I checked the oil and was down a quart so nothing major. C/E light is on as well as the Oil light.

Last week it was fine. Only thing that was different over the last few days since I drove it last was that it was kept outside in like 40 degree weather rather than being in the garage as normal. I drive it today and it's loud.

Anyone know what this could be?

 

first thing id do is see what the check engine light is for... borrow/buy a scan gauge, or go to autozone or some place where they can scan it for you

 

I hope you aren't driving it with an oil light on. If so, you might as well start planning on where you'll get your new engine.

 

Oil light on = OIL PSI UNDER 7 POUNDS!!!! Normal is above 10 at idle and 30 -40 at 2500 rpm. Stop driving truck, this is more important than codes. Oil light should come on at start up but go out when started in a few seconds. You can not safeky operate vehicle with low oil pressure.

A. Can be obstructed oil filter. Can be thin (5W20) or old and thin or diluted with ATF used as a flush oil. Can also be obstructed oil line or oil cooler which is on battery side of radiator. Oil needs to be "something" W40, not 10W30.

B. Can be oil pump. When it fails by cracking, it will produce some oil PSI, just not enough. The oil psi switch is on the side of the block on passenger side. You can unscrew it and screw in an oil PSI tester borrowed from auto parts store. There is a single wire on it. But with noise, it is unlikely that it is just the switch.

 

You have no oil pressure.
If you are driving it with the oil light on the engine is done for, put AAA on speed dial, drive it until it seizes up, call a tow truck and have it towed to where ever you want.
With a blown engine it is worth about $500.

 

Thanks for the feedback. On A) obstructed oil filter did you mean it can be "thinned" with those items or it can be obstructed due to those items?

It sounds like I should begin with an oil change. Am I understanding it likely isn't a valve issue because the oil light is on correct?

 

The oil pump has a by pass valve, so if the oil filter were blocked the oil would still circulate through the engine, so the oil filter is ruled out.
Second if the oil were thinned out by something, ATF, wrong weight of oil used or the like then yes your oil light could come on due to low oil pressure.
How long has the oil light been on?

 

Saw it for the first time today. Are we saying that since the oil light is on the engine is as good as seized? It was fine the last time I drove it 4 days ago...

 

Is the oil light staying on as long as the engine is running?
Or is it only coming on at a hot idle, like while at a stop light?
Does the engine only make noise when the oil light is on or all the time?

 

Light staying on. Just started today. Wife was driving it and noticed the oil light then listened and noted the sound. We stopped, checked oil, down some so added a quart. Level seems fine now. Yet the engine still has a valve/tick type sound like it needs oil. It does seems like the engine isn't getting enough oil.

Could this be an oil pump/pick pick up issue?