Strange thing happened this morning. Took the kids to school, everything working fine. Stopped by the store to grab some cold medicine and when I started it back up to leave it immediately dropped in idle to around 100-200 and was sputtering and spitting. Battery light was on, brake light was on. When applying gas it would level out to an extent but then drop right back down.


So I was about 4 blocks from the parts shop so I figured I would try and get it their to check codes. It seemed as long as I kept idle up it would move but when it dropped their was no power what so ever. Anyway finally got it up to about 30mph and got to the parts shop. Here is the strange thing. Once I pulled in lights went off and idle was fine. turned it off and back on, no issue. To me this sounds like a bad alternator. It was just replaced less then 6 months ago as well was the battery. Whats your .02?

 

Definitely something electrical. Did it blow your fuse for headlights?
I's start by checking your battery connections and grounds. Load test the battery and alternator. It is important to load test the alternator and not to do just a bench test.
Good luck. Keep us posted

 

Load test as in start with no lights or anything and then turn on lights and ac max? and when I say lights I mean the brake light and battery light went out. Also how if possible could I test the alternator output voltage?

 

ok so I think I got this pegged.


Upon further checking their is a oil on the bottom of the alternator. Checked the oil and its about half a quart low. It was just changed 3 weeks ago. I thought the camshaft seal was done right before I got it but the paperwork shows they did the valve cover gasket not the camshaft seal.


So Would it make sense to think that the up and down idle would be from the alternator dropping voltage>caused by oil leak>From camshaft seal<oil low

 

Oil on top of alternator is very often result of the front cam seal leaking. If at all possible, address that first. Otherwise, even after throwing a new alternator you will be in the same boat very soon. The Alternator and Brake lights on the dashboard turning on is an indication of abnormal voltage in the system. Having oil getting into alternator may cause erratic functioning of the voltage regulator or shorts between coils and thus erratic voltage output. All this together can cause the idle issues.
Fix the seal. If you are lucky, not much oil got into the alternator and it will continue to work after that.
I had a similar situation with the seal long time ago. I think I may have caught it earlier, but it still sloshed significant amount of oil onto the alternator. After replacing the seals, the alternator still worked for another several more years (finally replaced the OEM alternator after about 150k).

 

Is it possible that I could remove the alternator and run some water through it to clean out the oil?

 

Well, its possible to do that (physically). The question is - will it fix it or ruin it? Never heard of anyone doing this. Alternatively, you can disassemble it and just wipe down the oil instead of using water.

 

So a little update. Took it to my local shop as I ended up not having the time to do it myself. They said their was no leak and that the altanator was just bad. They said the cause of the low oil was that the Montero was burning it pretty bad. So they replaced the altanator with a life time warrenty and replaced a fuse and I'm back in buissness. Well this morning it started doing it again. Dropping in volts. So I guess back to the shop.