My new Ti is very sick...
 

Hi there, Im new to the forums, and unfortunately my first post isnt check out my new avus blue ti. Its check out my possible very broken ti...


Previous to this, the thermostat had been doing odd things, like taking a little longer to get to temp than it should. occasionally it would drop a little away from centre while driving..


I bought a 1998 318ti around a month ago. after doing around 1000 miles in it since purchase, I was around halfway on an 80 mile trip (last weekend), when it started misbehaving. Apologies for the detail, but as I have no idea what is wrong with my car, any info could be relevant.. The car became very stuttery under acceleration, with it really struggling to 'go'. It would find power and lurch occasionally, but the best way of getting it to move was almost teasing it up to speed.. I pulled over and let it cool down for a bit.


I checked the oil and water at this point. I had no option but to carry on driving. I got the car up to 70mph, and when cruising constantly it was barely noticable. however by the time i got to my destination (city driving, traffic lights etc) it was barely running, and shaking alot at idle.. Theres no sign of HG failure (no steam, no rad mayo etc), and im just wondering if any of you guys could diagnose the issue? Could the dodgy thermo have caused issues for the cat, and its become plugged?


At first I thought it may have been electrical/ignition, but the fact it got progressively worse confuses me! I guess whatever it is it may have fried the cat... making it barely running by the time I got there? Since then, I have started the car and it does run, but not well!


As you can tell, im no mechanic! if anyones got any ideas, please let me know. I'll get pics up soon, its standard at the moment, but a great colour :biggrin: One last thing, theres no warning lights on.... Im wondering whether sensors have been disabled/bulbs removed from dash before sale, to cover up an existing problem....

Let me be the first person to suggest what is always suggested here and that is to check for any air leaks in all the vacuum hoses and especially on the air intake boot.

to check the dash lights, turn the key on but don't start the car, they should all turn on

This reminds me. Can someone tell me if the CEL turn on if the alternator is bad?

o.k, dash lights do work! I dont understand why nothing showed up on the dash then... It was barely running by the time I got it safely parked up... would a vacuum leak etc not cause a dash light warning? could it maybe mass air sensor failure? Im guessing that WOULD give me a warning light tho....:confused:

After you check for air leaks, read this thread:

http://www.318ti.org/forum/showthread.php?t=20606

Your symptoms reminded me of this thread and thesk8midget fixed it.

clogged fuel filter?

1st - Water Temp - If it's taking a while to get up to operating temperature and sometimes fall below the 1/2-way mark, then your thermostat is probably stuck open. Buy a new one for about $30 and replace it. If you haven't replaced the water pump yet, now is a good time to do that and flush the cooling system as preventative maintenance. I drove my TI for a while with my thermo stuck open. However, when the thermo starts sticking like this it can easily break free and could get stuck in the closed position which would overheat the engine.

2nd - Stumbling upon acceleration could be caused by incorrect ignition timing which could be caused by any number of things. To help identify the actual problem, I'd hook your car up to a fault code reader even if your check engine light isn't on. The CEL bulb could be blown or even removed by the prior owner especially since you recently just bought the car. Hopefully it will throw a code or two, which will help you pinpoint the issue. Otherwise, it could be almost anything such as the Throttle Position Sensor, idle air control valve, cam sensor, a bad plug, bad plug wire, vacuum leak, etc... It's quite common for the TPS to need replacement based on the age of our cars or for the idle air control valve to be dirty and stuck. However, I'm not mechanic or expert, so at best I'm just guessing.

thanks for all the reply's! unfortunately, we had a look at it last night with one of my friends (bit of a home mechanic).. the spark plug housing was flooded, so we thought ignition/timing was the issue, and one cylinder probably was dropping out... cleaned all this, an started it up. ran perfectly until at temp (felt warm, thermo said 1/4), then got rougher and rougher...

ther did appear to be some knocking noise as well, but this was difficult to pinpoint, as it was running so bad the exaust was also rattling. On applying gas ther was also a little almost screechy noise like a slipping belt....

on opening the oil cap and giving gas (which makes it stutter)..... exhaust fumes:mad:

Piston ring?:confused:

ran fine cold however...?

You need to clean out or replace the crankcase breather.

It is normal for the engine to run poorly with the oil fill cap off.

The oil in the plug well is due to an old hardened valve cover gasket.

Just bring it to a mechanic and ask for a valve cover gasket and new crankcase breather.

thanks for the reply bu.ti-ful,

it wasnt actually oil in the spark plug well, just water. I have a feeling the engine bay may have been cleaned with a pressure washer at some point.....

the most concerning thing is the noises it was making when running rough, and the fact my mate says exhaust was coming from the oil filler cap when revved...

could this be from a broken/dirty/failing crankcase breather then?

were going to pressure test it tonight to verify whether it is a compression (E.g piston ring) problem...

I would definitely check the breather.

As far as exhaust out the oil fill hole, I suspect that is just crank case pressure which is normal, but controlled by the breather - which I suspect is clogged.

You are the second person on here to talk about water in the plug hole. I don't understand this because a hot engine should evaporate that quickly and why would it just be in the first hole?

I suggested to the other person to run the wiper fluid and see if it leaks under the hood.

thanks again,

sounds like it could be less work and $$ than I was thinkin, which would be nice. The whole plug recess was flooded with water. Prior to it breaking down it had been Stupidly wet here, with floods all over the place. I was actually towed 70 miles in the pouring rain after it broke.... Having said that, I still dont know how that volume of water got in there! didnt look or smell like coolant etc though.

I guess the noises could be just gases going in the wrong direction etc.

I'll update once we've pressure tested and checked the crank case breather..

thanks again for everyones suggestions!

Maybe the water was the problem?

Be sure to get it out before taking out the plugs!

One trick is to use the trigger from a Windex bottle.

Put the straw in the well and shoot out the water.

Also check the breather pipe that runs along the back of the engine from the cam cover to the breather valve. Id like to bet it will be either split or very soft and squishy! Common problem. The oil vapour degrades the rubber hose and it collapses and causes a blockage causing poor running.