S40 mystery problem
#1
12-10-2018, 06:20 AM
S40 mystery problem
I have a Volvo S40 2004 1.9L automatic. I have completely run out of ideas as to why I am bringing my problem here. My car started and was driving. Jolting/surging at low RPMs. When I release my foot off the gas it stalls out. When put into reverse it has a hard jolt and dies. When put into drive or any drive able function, stall. I do have an oil leak in the back of the passenger side engine area. Around the rear of the timing belt. It idles rough. Now before I am suggested I have a blown head gasket like most people have told me. I am hard headed on the fact it is not. I hear and feel the engine fuse block ticking in the engine fuse box compartment. This leads me to believe the voltage is getting cut out, causing the engine fuse to stutter therefore messing up the entire groove of my engine. I have tried different fuses to no avail. I have swapped all ignition coils and plugs. I have changed ignition switch fuel injectors,regulator, and fuel rail. I pulled the TCM fuse and the engine began to run completely smooth. Deciding it was a connection from the battery b+ to the fuse box I pulled out my air box, battery, and traced the cable to the box adjusting it. Put everything back together and the problems return, regardless of any fuses being in or pulled. Any ideas would help
#4
12-10-2018, 10:36 AM
If your OBD port isn't working, that would point to a computer / electrical problem (don't have a manual at hand to offer more advice).
Or... sometimes the "experts" at your local parts place really don't have a clue what they're doing. I'd suggest owning a cheap OBD reader - money well spent, since it saves you driving to the parts store and waiting for them to come out, hoping that their equipment and training are appropriate.
One other thing - I believe that the piston that controls the cam timing is oil-operated (and electrically controlled), and is located near the cam pulleys. If it's not working, you end up with a lumpy idle and poor power, etc. You DO have to figure out where the oil is coming from anyway, so it's probably worth tearing enough parts off the top of the engine to see if that might be the problem. But I'm thinking that it should throw a code - again, you might want to get a second opinion / read on that OBD port to see if someone else (including you with your own shiny new OBD reader) can pull some codes. The cost of that reader is a small fraction of the cost of all the parts that you've already "thrown at the problem"...
Or... sometimes the "experts" at your local parts place really don't have a clue what they're doing. I'd suggest owning a cheap OBD reader - money well spent, since it saves you driving to the parts store and waiting for them to come out, hoping that their equipment and training are appropriate.
One other thing - I believe that the piston that controls the cam timing is oil-operated (and electrically controlled), and is located near the cam pulleys. If it's not working, you end up with a lumpy idle and poor power, etc. You DO have to figure out where the oil is coming from anyway, so it's probably worth tearing enough parts off the top of the engine to see if that might be the problem. But I'm thinking that it should throw a code - again, you might want to get a second opinion / read on that OBD port to see if someone else (including you with your own shiny new OBD reader) can pull some codes. The cost of that reader is a small fraction of the cost of all the parts that you've already "thrown at the problem"...
#5
12-10-2018, 04:39 PM
Senior Member
Your oil leak is very likely the cam seal or the vvt gear right in front of it. Just take the plastic engine covers off and take a peek. If most of oil is in behind the gear it’s likely the seal. If most of oil is all over gear it’s likely the gear itself leaking.
Here’s the thing: if it’s a leaking cam seal, they don’t typically start leaking for no reason. They leak because the pcv maintenance has not been done.
the oil leak should be addressed either way. The bad news is that I don’t think that leak is causing your cut out issues
im at a loss there. I would have replaced the same stuff you did.
didcyou repoace the engine coolant temp sensor? How about the upstream o2 sensor?
im with you. I don’t think it’s a bad HG. Unless of course the oil is milky or your coolant is blowing hoses.
codes need to be read for sure. Otherwise you could keep throwing a fair number of parts at this.
Here’s the thing: if it’s a leaking cam seal, they don’t typically start leaking for no reason. They leak because the pcv maintenance has not been done.
the oil leak should be addressed either way. The bad news is that I don’t think that leak is causing your cut out issues
im at a loss there. I would have replaced the same stuff you did.
didcyou repoace the engine coolant temp sensor? How about the upstream o2 sensor?
im with you. I don’t think it’s a bad HG. Unless of course the oil is milky or your coolant is blowing hoses.
codes need to be read for sure. Otherwise you could keep throwing a fair number of parts at this.
#6
12-11-2018, 01:41 AM
When the tcm fuse was pulled, car ran smoothly(limp mode) Pulled battery and air box to reach more wir, re arranged it in fuel box, tightened connectors. Engine was back to running terrible stalling and ticking from the fuse box. That’s my idea on fusebox and more so likely the positive battery cable (b+) having some sort of sorting which is causing the engine fuse to not maintain proper engine connections. I have cleaned and try running the Maf unplugged to no avail. The oil leak is coming from somewhere around the pullies which if the above poster stated was true then the oil leak essentially would be caused by the battery cable culprit. My question is does all this make sense before I presume my work? I will be replacing the battery cable, going to the junkyard and would like to know all possible options will I need to grab an alternator while I’m there? P.s my spark plugs were all black from fuel to rich. (Fpr and fuelrail both swapped$
#8
12-11-2018, 04:23 PM
The black fouled spark plugs are a clue. If your Coolant Temp Sensor is broken and reading full cold then your car runs crappy as the ECM dumps tons of extra fuel into the engine, Check your CTS up by the thermostat housing.
I would also find out is why you cannot pull the codes. If you have a data line that is bad and you cannot talk to the ECM then odds are your ECM cannot talk to the other computer modules on the CAN BUS. You will need someone with specialized scan tools.
You can check for combustion gases in the coolant with a kit from the parts store. It works very well.
Do you live in an area that heavily salts the roads in the winter?
I would also find out is why you cannot pull the codes. If you have a data line that is bad and you cannot talk to the ECM then odds are your ECM cannot talk to the other computer modules on the CAN BUS. You will need someone with specialized scan tools.
You can check for combustion gases in the coolant with a kit from the parts store. It works very well.
Do you live in an area that heavily salts the roads in the winter?
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