I just bought my first audi a4 1.8t. On cold start up it going up to like 1200 rpms and studders for maybe 30 seconds then evens out to about 800rpms. Check engine says cylinder misfire on start up. Coil Packs and plugs were replaced. Any ideas?

 

Change your coolant temp sensor - it's $20 and is the root of a lot of evils on these cars.

 

Also, pull the plugs and see if one of them has oil on it..

 

Have the codes scanned at any auto store for free. or if you have a Vag-com that's best. P0300 multiple and P0301-04 the last number is the cylinder. If it also shows multiple that might be because if one misfires it will drag in more
(misery loves company)

The temp sensor is the primary one of three sensors that tells the engine to start up on"cold start" or not. It would probably make your gage show strange readings or not work if it was that. But it's cheap anyway and does seem to fail on quite a few people.

Try This;

When cold-or the situation when it would normally misfire. Pull the misfiring plug. Using a suction pump like for brakes with the separate canister and tubes. slide a tube into the lower section of the cylinder and try to suck any fluid that may be in there out. If it is Oil- Valve seals, If it is Coolant-Probably the Head gasket. If you do not get anything then try taping the snot out of a swab or white pipe cleaner to a piece of wire and try that way. It may just be a little but enough to seal the rings and cause detonation.

Solutions to both;
The valve seals can be done with the head on the engine. Seals cost 1 dollar a piece. Get VITON not the black rubber ones I ordered mine from here; http://www.rmeuropean.com/audi-parts.aspx#
Also order your timing cover, sensor cover and cam adjuster gaskets, extra valve keepers. You will need an external valve compressor and to a search on the subject.

Head gasket;
If you replace it use INDIAN HEAD sealant on it. I didn't and had to go back in and use it. Do not scrape the heads at all. Use a good cleaner and plastic not metal scrapers.
I used easy of but I disassembled the head. It will eat the seals.
OR
Pick up a can of Bar's leak head gasket repair for use with coolant-30 Dollars. It works and will pack silicate glass and copper into the leak. All engine manufacturers use it. Follow the directions.

 

^ Exactly!

Well put jackmup!

 

but the car runs fine after about 30 seconds. Could this still be a head gasket or valve seals. I would think that would effect the engine during driving or while running. I will check this out. Any other info or help is greatly appreciated. I really want to get this problem solved. I mean its not major because it only happends on cold start which is every morning and will go away after about 20-30 seconds.

 

These are the codes brought up when the guy scanned it at best buy before installing some audio.

P1128
P0300
P0302
P0301
Pending P0304

 

P1128 - Long Term Fuel Trim - System Too Lean Bank 1

the others are Mis-fire codes - cylinders 1,2 and 4.


I doubt its a head gasket issue... start by doing the basic: check/clean MAF, wires, plug wires, plugs, coils... replace fuel filter.. replace fuel regulator...check for vacuum leaks...clean TB..etc..

 

well it was my maf sensor. also the guy i bought car from put autolight plugs in the car! so i put oem plugs, oil change, k and n air filter, new oil filter and maf sensor and my problem went away. new problems are my water pump is leaking and my turbo is leaking. any sugestions on what to do. should i buy a new turbo or have it rebuilt. shop said he thinks its coming from feed line. i can change the water pump just wondering how hard it is to do? Any links would be helpful to help fix these problems. i can do the work its just iv never worked on an audi before. thanks to all.

 

Good place with lotsa links... pick your car....

http://www.audidiy.com/a4platform.html