94 Jetta, series of problems

Ok, so 2 months ago otw home form work my girlfriend calls me and tells me she cant shift into 2nd gear like theres a brick wall there. I take it to a few shops and all have the same diagnosis, transmission is toast. I paid $1,200 to get it rebuilt, got it back and now have a slew of problems.

Keep in mind, this was one of the best, if not the best running vehicles I have ever own. I bought it in Sept last year and it now has 93k miles on it. I was very pleased with the purchase and was expecting some things to go wrong as with any used vehicle purchase.

Heres my problem.

OTW home after about 3 miles the oil light came on and was beeping like mad. At that same time, the AC stopped working and the temp was about 240 degrees (I didnt notice what the temp was before the oil light came on). I talked to the dude who fixed the car and he said he didnt touch the entire left side of my motor, just took apart the right side where the transmission was. After some toying and whatnot, I found a pinhole leak in a the hose that came out of the water pump. The AC is still not working and after a oil sensor change and some creative test driving we discovered the oil light comes on at 1950 rpms and shuts off at 2100 rpms. The only way to get the light and beeping to stop is to rev the engine above 2100 rpms and the light/beeping stays off until the needle drops to idle and comes back up to 1950 where it starts again.

My question is....how on earth could a perfectly running vehicle have so many problems all at once the very day the transmission was fixed? Normally I would accuse the guy of tampering with crap to make more $$ off me to fix the other stuff, but he goes to church with my parents. They have known him for years and trust him very much, in fact just bought a car from him earlier this year.

Does anybody have any ideas on what all the problems are? BTW, I replaced that funny shaped hose that had the leak and now the heat stays around 180degrees and we've done an oil/filter change, made sure there wasnt too much nor too little oil in there (took it to a different shop for the oil change). Its a 94 Jetta (CLX I believe) 2.0 with AC. Belts and everything else is fine and working normal aside from those mysterious problems.

You are suffering from symptoms that could be caused by a lot of things. If the 94 is the same as the 92, there are two sensors: one on the cyl head, one on the oil filter holder. The one on the oil filter holder will only trigger an alarm when RPM's exceed 2000. The pressure could be low at that point with RPM < 2000 and you wouldn't know. When you rev up to 21-2200 RPM's the oil pump spins faster and pumps at a higher pressure. It may be that you are running right on the threshold. If you can get an oil pressure tester (they don't sell them at most chain auto parts stores - good luck, I found one at harbor freight for $10) connect it in place of the sensor, let the car idle and see how low the pressure drops. The setpoint for the sensor is stamped on the underside of the hex portion. If the pressure is ok replace the sensor. They only cost a couple bucks on line. If the pressure is ok and replacing the sensor doesn't help it's probably the sending unit that interprets the signal from the pressure sensors. If the pressure is low three possibilities are high temperature, oil leak, or a failing oil pump. I had an impeller fall off my water pump (which I had never even heard of happening prior to this) and because of the location of the temperature sensors, it seemed like everything was ok when there was actually no coolant circulation at all. If you need a new oil pump, you can get a new oil pump online for about $45 at sasponline.com. You can check other peoples prices as well. The gears in the oil pump should have a gap less than .08 inches if I remember correctly. If you test with an oil pressure gage, make sure you note the initial pressure and let it idle half an hour or so to see where the pressure goes. Don't space and take it for a test drive with a loose gage still attached and loose beneath the hood. I almost did so. Watch our oil level, if you're using a lot of oil, a leak is a likely cause of the problem. Given all of your symptoms, I'm betting on the water pump. The A/C condensor sits against the radiator and if it's too hot it will keep the A/C from working. Recheck your belts as well. All your symptoms could easily be connected to a single problem.

Ok, thanks for the info.

I think I came across a discovery though. I really dont know too much about cars....at all. But, I noticed after my step-dad replaced my hoses for me, the next day we couldnt get the oil light to come on once no matter what rpm we were at. We havent done anything to the car since I posted so everything on it is the same. Except...when I looked inside to see if all the pulleys were spinning with the belts (mainly the AC since its still out) I noticed that when he put the top hose back on, that he had accidentally bent the oil dipstick and broke it. The only part thats broken is the plastic part just above where it makes the seal on the tube when you put the dipstick all the way back on. Now I'm thinking there's a blockage somewhere in the engine. I know theres some kind of vacuum in the motor, I just dont know where or what for. But I'm thinking if it has anything to do with oil pressure, then thats my problem and the broken dipstick is allowing enough suction for there to be a vacuum.

Is my theory way off base or is what I'm thinking a possibility?

up till 96 2.0 have lots of problems with oil pumps failing.

If your dipstick tube broke than the bits of red plastic problably fell into engine and are clogging up the pickup tube for the oil pump in the oil pan. There are 2 sensors for oil pressure, one on cyl head and one on oil cooler (look by oil filter). Sometimes the electrical connector doesnt stay on very good and causes the light to come on.

And sorry for the 1200.00 rebuild on the transmission. You can buy a new manual from vw for 1200.00 and auto for 1400.00.

My 94 GL 2.0 5SP A/C clutch would not engage, it was a two wire coolant sensor on the flange mounted on the head. The coolant sensor is switched either open or close, it should be closed until the coolant is hot enough to shut the a/c off. Just a possible cause.