Hello everyone,

i hope you are all doing well, i'm a new member to the forum & i would like some help please.

I own a 2005 v6 2.1 petrol engine with only 57000 KM, about a month ago my car started to go into limp mode "rpm wont rev past 3000" at first i found the rubber of the breather hose was damaged so i fixed it but unfortunately my car still goes to limp mode every now and then & there is no engine light & no warnings of any sort! the car sometimes drive normally from cold start and suddenly go to limp mode.

If i take the car to the dealership they will charge me $200 just for connecting it to the computer as a result, i was looking to get your advice first as maybe it wont be much difficult to sort it out my self.

Your feedback & suggestions will be highly appreciated,,

 

majidessa, first off, welcome to the forums. Lots of good information and people here. So, sit back, do some more reading and I am sure we can get you taken care of. But, we also ask a small favor from you. Please stop by the "New Member" Section and give us a quick note about you and your car. We pride ourselves in being a better car group and as part of this, we like to get to know one another and keep things on more of a friendship level. This will also give you a chance to meet those that make this place what it is.

As for your problem, I want you to try something for me. If you look on the end of your turn signal stalk, you will see a button that says "TRIP". What I want you to do is to depress that button and hold it down. While holding it down, start the car. As soon as the car starts, look at the message center in the instrument cluster. When you see it say "TEST" or "Engineering TEST", release the TRIP button. You will then depress the TRIP button like 15 times till you see the message center say something to the effect of "DTC XXXX" where XXXX is either a letter or number followed by 3 more numbers. Write it down and then press the TRIP button again. If it says "DTC XXXX", write that number down. Repeat till you see the message center say something other than something starting with "DTC". Post those numbers here and I can decipher what codes your car has stored in memory and this may help me figure out where you are having issues.

Another trick that you can do is with the motor semi cold (ensure the A/C is turned off so the engine fans are off), you can use a cigar to blow smoke around the intake to see where the smoke is getting sucked into the engine. if you can see the smoke getting sucked into the engine other than at the very front of the engine by the air intake, then that is where you are having a vacuum leak. if you don't smoke, you can also take a long piece of tygon tubing (about 1.25 meters in length by say 6mm inside diameter) and hold one end near your ear (DO NOT!!!!!! form a seal to your ear). and then pass the other end near all the joints where parts of the intake join and along any rubber/plastic piece of the intake. If you can hear a sucking sound, then that is where your problem lies.

One last thing. Wehn was the last time you cleaned the Mass Air Flow Sensor? That could be causing your problems if that is dirty. If you need directions on how to clean it, let us know. It is really simple and is fairly inexpensive to do.

 

Hi Thermo and many thanks for your help,

I've just introduced myself under the new member section and thanks for pointing that out.

Unfortunately i tried depressing the trip button but it did not work & no messages appeared in the instrument cluster.

However, i took the car earlier today to a mechanic & he was able to read the code P0174 only, i know this code was mentioned a lot but i was not able to limit it to a specific cause. I also would like to point out that when my car goes into limp mode & after i depress the gas pedal the car starts to cough especially from the air filter section so maybe be this would help in better determining the cause.

So once again thank you for your help & i'm looking forward to hear from & give me your insights.

 

majidessa, code P0174 is telling me that you have a vacuum leak on the bank 2 side of the engine. This would relate to the cylinders on the radiator side of the engine. Because of this, your problem most likely is either the IMT valves or the brake booster line.

Do you have a can of ether/starting fluid around your place. if you do, another quick check that you can do is to spray a little bit of the ether on the IMT valve joints and see if the engine RPM picks up a little bit. If it does, then you have confirmed that you have a bad o-ring on the IMT valve. You can then spray the connections on the intake where there are hoses coming off. Again, if the RPMs pick up, then whatever you just sprayed is leaking. Just be careful not to get the ether near any sparks.

This may help you find where you are leaking from and then give you a point to start looking at more in depth to figure out what needs to be done.

 

Hi, can someone please illustrates where the IMT valaves "O rings" are located in a 2.0 engine ?

Thanks

 

majidessa, please work with me here as I am not infinitely familiar with the 2.0L engine (we only have the 2.5L and 3.0L engines here in the US), but the 2.0L engine is based off of the same block, so, a lot should be the same.

If it is like the 3.0L engine I have, if you open up the hood/bonnet of your car and rest your hands on the intake, near your left hand you should see 2 black circles pointing towards the fender of the car that are roughly 10cm in diameter. Those are the IMT valves. In trying to find a picture of the motor, I found one that showed the IMT valves in a slightly different location. Starting again with your hands on the intake, your hands would most likely be on top of these 10cm diameter plates. They are pointing straight up.

As for the o-rings. You will notice that these plates are held in place by 2 bolts (8mm socket removes them). Once the bolts are removed, disconnect the electrical connector and then pull the IMT valve out of its hole. Just under the top of the IMT valve, you will see either a yellow or green line. This is the o-ring.

Replacing the o-ring is pretty straight forward. The only trick I can say is if the 2.0L is like the 3.0L motor, you can not remove the lower IMT valve. What you end up doing is backing out the IMT valve as far as you can so you can use a small screw driver or something else to get under the o-ring (make sure not to scratch the under lying surface) so you can stretch the o-ring slightly and get your finger(s) under the o-ring. From there, you can stretch it some more and pull it off by going over the large plate on the end (where you remove the bolts from). The new one will go on reversing what you just did.

 

I can only find 1 IMT valave which is on the left top corner of the mainfold

 

majidessa, well, it appears that you only have 1. The one picture I saw seemed to have 2 in it. Maybe I saw the picture wrong. Replace the o-ring on the one IMT valve and go from there.

If this doesn't help, then I would break out the starting fluid and start searching the joints to see where the leak is then. I would hate to send you on a wild goose chase replacing parts one by one without any definitive proof that it is wrong.

 

Hi again, i changed the imt o ring but it did not help, my car still can't go above 3000 & i still hear a mild coughing noise coming from the intake after i depress the pedal, this only happens sometimes especially if it is idle for 10 minutes or so, when i first start the car it runs smooth but after a while it just goes to limp mode sometimes it even goes back to normal.

Again the error code that i got was P0174 & DTC 9205 (instrument display) now i'm thinking to clean the injectors & replace the spark plugs but i'm not sure if it would solve the problem! i would appreciate your thoughts on the matter

 

Maji, the P0174 is for a vacuum issue. So, replacing the plugs and cleaning the fuel injectors is not going to cure anything. With this being said, doing the plugs is probably not a bad thing and while you are in there, replacing at a minimum the upper intake seals would be well worth the low cost of the seals. If you are that far into the engine, a few more minutes and you will be at the lower intake seals too. If you do some looking around here, I have a few references to the Felpro gaskets that are for the 2.5L and 3.0L engines. Should be the same ones for your car. BUt, may want to do some looking around to verify. The gaskets run $50 USD for both sets (one set is like $15, the other is $35).

If you have the car idling, I would say your next step would be to use a little starting fluid and spray any joint you can see on the intake. If you hear the engine RPM pick up, that joint is where your vacuum leak is. If you don't like the idea of spraying a flammable substance on the engine, the other option you have is to get yourself about a meter of 1/4" tygon tubing (a little more is ok, enough to go between the engine and your ear). While holding the tubing close to your ear (DO NOT!!!!!!! form a seal between your ear and the tubing), run the other end against all the joints of the intake. If you hear a sucking sound, where the end is against the engine is where your vacuum leak is. You can then atleast know where the leak is coming from and know what parts that you must have to fix your problem.

 

Without going too much deeper into the engine, I would look at a exhaust restriction, like maybe a catalytic converter. The engine will only bring in as much air as it can push out. I have a lot of experience with being a retired Master Tech for VW Porsche Audi, for 28 years, and a VW ring wearer. Sometimes simple problems can cause big headaches. My Journeyman always had an expression...KISS, or keep it simple stupid. Try disconnecting your exhaust before the converters, and see how the engine revs then. It is a fairly simple test and may pop a code, but they are easy to erase, with a $50 code scanner and eraser, from Ebay or Amazon. Best of luck.....Mike

 

I think Thermo has the right idea with the vacuum leak and the intake manifold gaskets. I have never seen anything on here where that code was caused by anything other than a vacuum leak.