6th Gen ('00-'05): 3.4L Must warm up before being driveable??
#1
02-10-2016, 05:41 PM
3.4L Must warm up before being driveable??
So as of a few weeks ago I suddenly have a very inconvenient problem. If I don't start the car and let it run for 15-20 minutes before driving it, it is VERY sluggish. I've just noticed that I can figure out when it's ready to drive by attempting to rev it up while sitting in park. For some reason it won't go over 2,000-2,300 rpm's until it's been running for a while. If I take off in it before it will rev above that, then it's almost impossible to get it over 25mph until I get 2-3 miles down the road.
I do have a slight coolant leak from the lower intake manifold that has been leaking for a few months that I haven't had the time or money to repair. Could it be something to do with that? Maybe cold air getting sucked into the intake?
I've just finished giving it a oil change and a new battery, also. I figured it could be lifters not pumping up all the way, or system voltage issue. I had the battery tested and it was indeed bad so I replaced it, but it didn't fix the main problem.
I do have a slight coolant leak from the lower intake manifold that has been leaking for a few months that I haven't had the time or money to repair. Could it be something to do with that? Maybe cold air getting sucked into the intake?
I've just finished giving it a oil change and a new battery, also. I figured it could be lifters not pumping up all the way, or system voltage issue. I had the battery tested and it was indeed bad so I replaced it, but it didn't fix the main problem.
#3
03-09-2016, 11:23 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,156
Do you have any Check Engine Codes? This is the best starting point.
Cold air is typically good for car performance. Depending on how your intake is leaking might be part of your problem. I assume it's the lower intake gaskets that are leaking. Assuming that is the case, if the gasket has failed to a point that a coolant port and an air intake port are both compromised, you may have coolant getting into the cylinder (if it's a high enough volume, you may see white smoke out the exhaust). But I am doubting this is the primary issue (as it would get far worse as the car got hot and the cooling system built more pressure). So I'm going to say this is not the issue.
The 3400 engine (and earlier 3100) are known for lifter/valve chatter that is normal. Unless you have some unusual sounds while the engine is running, not sure it's an oil issue.
You indicate the engine has to warm first. Not going over 2000-2300 RPM, is that also the case if you goose the gas while in park? If so, I am suspecting a possible failed sensor that influences fueling. MAF sensor should not be in play yet since the car is cold (the MAF has to warm to operating temp first). But you can do a quick test with the MAF, with the car off, unplug it and see if it changes anything. My primary thought is the upstream O2 sensor. After that I would start inspecting things like a clog in the exhaust system (such as a clogged cat, but I would suspect the problem to get worse when the car heats up) or worn out plugs and wires.
Cold air is typically good for car performance. Depending on how your intake is leaking might be part of your problem. I assume it's the lower intake gaskets that are leaking. Assuming that is the case, if the gasket has failed to a point that a coolant port and an air intake port are both compromised, you may have coolant getting into the cylinder (if it's a high enough volume, you may see white smoke out the exhaust). But I am doubting this is the primary issue (as it would get far worse as the car got hot and the cooling system built more pressure). So I'm going to say this is not the issue.
The 3400 engine (and earlier 3100) are known for lifter/valve chatter that is normal. Unless you have some unusual sounds while the engine is running, not sure it's an oil issue.
You indicate the engine has to warm first. Not going over 2000-2300 RPM, is that also the case if you goose the gas while in park? If so, I am suspecting a possible failed sensor that influences fueling. MAF sensor should not be in play yet since the car is cold (the MAF has to warm to operating temp first). But you can do a quick test with the MAF, with the car off, unplug it and see if it changes anything. My primary thought is the upstream O2 sensor. After that I would start inspecting things like a clog in the exhaust system (such as a clogged cat, but I would suspect the problem to get worse when the car heats up) or worn out plugs and wires.
#4
03-10-2016, 09:46 AM
Thank you for your response the_maniac. The car does have quite a few check engine codes i'm sure, but I haven't taken it to have it scanned again lately. Back before it started doing this it had a lot of different ones that I had cleared out after I did a tune up and fixed a few things. I will take it and get it scanned again asap.
As for smoking, it's not smoking much at all. Smells like it may be running a tab bit rich but it's always done that. As for the cat, it's been removed and straight piped.
On to the revving. When I first start it up after it sits all night, it will start up normally and then idle fine for about a minute or so. Then it will start acting like it's loading up and start having a rough idle. It will then stutter and get really low in rpm and then on its own it will rev back up to about 1500 or so rpm and then go smooth idle for a few more secs and then back to rough idle. Sometimes it makes it through all of this without dying a few times, and sometimes it just cuts off. If you get in the car and try to just stomp it, it will bog it down.. and when you let off the gas it will rev back up a few hundred rpm's. But if you just give it maybe 15-20% throttle and let it build up to about 2k-2500 rpm's it will make it there.
This is the strangest problem i've ever had with a car, tbh. The intake gasket leak is on the lower plenum where the manifold meets the head btw. Crazy thing is.. after it gets warmed up and past this phase it runs perfectly normal. No hesitation, no loss of power, no problems whatsoever.
As for smoking, it's not smoking much at all. Smells like it may be running a tab bit rich but it's always done that. As for the cat, it's been removed and straight piped.
On to the revving. When I first start it up after it sits all night, it will start up normally and then idle fine for about a minute or so. Then it will start acting like it's loading up and start having a rough idle. It will then stutter and get really low in rpm and then on its own it will rev back up to about 1500 or so rpm and then go smooth idle for a few more secs and then back to rough idle. Sometimes it makes it through all of this without dying a few times, and sometimes it just cuts off. If you get in the car and try to just stomp it, it will bog it down.. and when you let off the gas it will rev back up a few hundred rpm's. But if you just give it maybe 15-20% throttle and let it build up to about 2k-2500 rpm's it will make it there.
This is the strangest problem i've ever had with a car, tbh. The intake gasket leak is on the lower plenum where the manifold meets the head btw. Crazy thing is.. after it gets warmed up and past this phase it runs perfectly normal. No hesitation, no loss of power, no problems whatsoever.
Last edited by dns; 03-10-2016 at 09:49 AM.
#5
03-10-2016, 12:09 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,156
Based on some of what you mentioned, sounds like a possible bad sensor, which is causing the PCM to do things it shouldn't.
Get the codes scanned and begin resolving those. Without doing further research my gut says a bad upstream O2 sensor (especially if the car is running rich).
Get the codes scanned and begin resolving those. Without doing further research my gut says a bad upstream O2 sensor (especially if the car is running rich).
Last edited by The_Maniac; 03-20-2016 at 09:48 PM.
#7
03-10-2016, 05:47 PM
Got it scanned on the way home from work. Apparently the only code right now is Bank 01 Sensor 01. It's looking like it is indeed an O2 Sensor! Good call maniac! I'll update again after I replace it soon. Hopefully this thread ends up helping someone else some day also.
#9
03-20-2016, 07:02 PM
Ok just picked up the upstream O2 sensor. The code was reading Bank 1 Sensor 1. Does any of you know this sensor location by chance? I'm googling but haven't figured out which one it is yet, and don't want to swap out the wrong one lol.
EDIT: Just did some searching on the site and apparently it's located on the rear exhaust manifold. Gonna head outside and locate it and swap it out.
EDIT 2: Found it pretty easily on the rear manifold between motor and firewall. Had to run back to parts store last night to grab a sensor socket to remove it, but it came out fairly easily with the help of some leverage from a breaker bar after I removed the front motor support arms and rocked the car forward and then hit the e-brake to hold the motor twisted forward (hehe). Idled and ran much smoother, but check engine light stayed on. Also, in the process, I found my manifold leak!! Noticed coolant bubbling out around the corner of the manifold and it turns out that it was just the front driver's side manifold bolt being loose! I slid a 10mm down in there and tightened it up about 3 turns and now no more leaky. That had been plaguing me for months! So after I finished everything up I went ahead and disconnected the battery to reset the computer. I'm about to go hook it back up and go pay some bills in it now and see how she's acting. I'll update once again with results of idling/running from sitting overnight.
Final Results: Hooked battery back up this morning and fired it up and it ran perfectly. Check engine light is out and car is idling beautifully and requires no warm-up to drive. Coolant leak also gone, lol.
Thanks for the help guys!!
EDIT: Just did some searching on the site and apparently it's located on the rear exhaust manifold. Gonna head outside and locate it and swap it out.
EDIT 2: Found it pretty easily on the rear manifold between motor and firewall. Had to run back to parts store last night to grab a sensor socket to remove it, but it came out fairly easily with the help of some leverage from a breaker bar after I removed the front motor support arms and rocked the car forward and then hit the e-brake to hold the motor twisted forward (hehe). Idled and ran much smoother, but check engine light stayed on. Also, in the process, I found my manifold leak!! Noticed coolant bubbling out around the corner of the manifold and it turns out that it was just the front driver's side manifold bolt being loose! I slid a 10mm down in there and tightened it up about 3 turns and now no more leaky. That had been plaguing me for months! So after I finished everything up I went ahead and disconnected the battery to reset the computer. I'm about to go hook it back up and go pay some bills in it now and see how she's acting. I'll update once again with results of idling/running from sitting overnight.
Final Results: Hooked battery back up this morning and fired it up and it ran perfectly. Check engine light is out and car is idling beautifully and requires no warm-up to drive. Coolant leak also gone, lol.
Thanks for the help guys!!
Last edited by dns; 03-21-2016 at 04:56 PM.
