Misfiring issues in my 1.8T VW Passat AWM
Asked by Adammahon Mar 01, 2014 at 10:08 PM about the 2001 Volkswagen Passat GLS
Question type: Maintenance & Repair
I've been having a misfiring issue with my car. I determined it wasn't the coils, I replaced
the spark plugs, and also the angle sensor but it's still misfiring. My mechanic thinks that
my Cam chai tensioner is bad do to a rattle my car makes after starting it up (cold) for
about 30 seconds. Could you please help me out and let me know if this would even be a
cause for misfiring cylinders. I'm so lost and I would like to resolve this as soon as
possible.
14 Answers
Is check engine light on? If so what are the codes?
The rattle could mean you need an oil change or the oil pump could be clogged. Before you change the tensioner check these... I don't think these would cause a misfire so check fuel pressure and the codes first, check for air leaks, broken hoses or check valves are common issues.write what in here any updates to help more
I put new NGK Laser platinum spark plugs and also the Camshaft position sensor.
When I bought the car 3 months ago I changed my oil with SAE 5W-40 Castrol EDGE SPT 505.01 spec
This code is for a timing issue, it could be the timing valve stuck or damaged or even the timing itself that could be off. One question, does the engine sounds rough? You mentioned a rattle you will need to check where does it comes from. Could be low oil pressure and cause the timing valve to work incorrectly or the tensioner could be damaged also they both make rattle and also if pressure is low the lifters can cause rattle sounds. You could have the oil pump clogged. You need to check those to continue.
The rattling is coming from the back of the engine by the windshield. It only occurs for a short period of time when the engine is cold. The mechanic I was going through thinks it's the Cam chain tensioner but I think he is starting to just guess and I'm going to move on to another mechanic. Other then the rattle when it's cold it runs good, besides the hiccups from the misfires. Thanks for trying to help me out Hector!
your welcome. it is common for the tensioner to rattle when the oil pressure is low and it is common to have issues in the oil pressure when good maintenance is not met on that particular engine. damages to the bearing on the connecting rod cause oil pressure to escape and cause a lot of problems many as the one you have. your mechanic needs to remove the crankcase to check the bearings if necessary replace them and the oil pump. you can check the rail on the tensioner to see if it's broken but this is not usual, in fact it's very rare. hope this helps some more
And all of this could cause a misfire issue?
I read that this 1.8T engine has a unlimited mileage warranty on 1997- 2004 model year vehicles, is this true?
the tensioner is supposed to change engine timing if timing is wrong could cause a misfire, so the answer is yes... for the warranty i don't really know because i am outside the US and these things vary too much.
The extended warranty is for eight years starting when the vehicle was new. There is no limit on mileage. The warranty covers subsequent owners.
I also have a misfire issue. I have changed the plugs, cylinder 3 and 4 coils. I still show codes p300, p303, and p304. Please help
Rattle with misfires sound like what I'm trying to diagnose. Likely a clogged oil pickup screen, preventing oil into the head, and also preventing the cam chain tensioner from tensioning properly (oil pressure driven)... thusly causing slight cam adjustment and misfire. My misfires are slight. Just like bup bup blips in the idle. But the rattle is very noticable. It seemed to get more quiet running some engine cleaner through it with the oil. Basically a solvant, and smells like fuel. So my guess is also this. Anyone have experience changing out the pan on these. A nightmare from what i hear.
