I have a problem with hard starts and bad emmissions which I think are caused by wet spark plugs. They were changed few months ago because the car couldn’t start, all of them were black (some of them had 1 some 4 “legs”, God knows who put them). Now few months after, again, they are all blackish but the one on the fourth cylinder is wet, not sure if thats oil or fuel or both but seemed more like oil judging by the texture (didn’t smell it because the mechanic was inspecting them). If you could help me find the root of the problem it would be fantastic…
(Diagnostic shows no codes, but the check engine light comes from time to time, seems like it dissapears after reving the car a bit)
You gave us ZERO information about what you are working on… we should not have to search your past post to find it… sorry but we see a lot of post everyday… lol
Year Make Model and ENGINE size (ci or L)
Also did you put the correct OEM spark plugs in it…
If the CEL is coming on and going off again then the ecm should have picked something up but not enough to store a code, however there should be a pending code and maybe a history code… Have you checked for freeze frame or even looked at live data to see of anything looks out of spec or borderline??
Have you run a compression test, both dry and wet??
What are you calling legs?? Do you mean the ground electrode??
BTW Pictures are worth a thousand words, so posting pictures of you plugs would be a big help…
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First of all thanks for the reply! The car is Opel/Vauxhall Tigra 1.6 16v (106hp). These “new” spark plugs, changed few months ago, are OEM. Ones before them were put in “pairs” two with one ground electrode and two with four ground electrodes. These new ones are with only one. So let me begin… I bough this car last winter and it was in terrible shape. It wouldn’t start without pressing the gas pedal, revs were stuck sometimes at 1500, 2000, 3500 and fuel consumption was quite high. Also somebody did have fun with electronics, sometimes I couldn’t turn off the car without having lights shut off haha. However, I sorted out many of these problems but not all. Firstly my mechanic changed the Oil, the choice fell for Shell Helix HX5 15w40 and all of the filters, after that he cleaned the throttle body and changed the stepper motor which caused high revs on idle, after that fuel pressure regulator was changed which pissed petrol and today we changed the crankshaft position sensor. Now about the diagnostics,few days earlier I had the codes read, didn’t write them up sorry, but they were telling I had problems with the sensor i changed today, throttle position sensor, egr, and immobiliser, all of them were deleted that day but the tps and cps came back, they were deleted today again and now there are no codes, but I would say the tps still comes up but I’m not really that concerned about it right now. My main problems right now are long cranking time and poor start and blueish/greyish smoke coming from the exhaust (registration expires in few months and I’m concerned about the emmisions and mot) also the petrol smell. Today when I came to pick up the car it was working on three cylinders, just like before the sensor change (except before that on higher revs it would start working on all four?), I took a quick tour, tried to rev it up a bit but no change. Then my mechanic checked spark plugs, as I said how they were, dried the one which was wet and then put them back. Did the tour again, nothing, all the same. He than sat, rev’d the car at about 5k rpm for about 30sec, while doing that from the exhaust was coming grey/blueish smoke but not consistently, it was like exhaust manifold was clogged up and it started to breath again, not to tell about the terrible smell. Car then started working just fine and pulling just fine. He told me that I should should check the injectors and open the engine. This engine was consuming oil new and I’m aware of that, but I’m pretty sure that it shouldn’t smoke that much and make that type of smell, if helpful I could make a video tommorow. About the cranking,I tried the ignition metod, turning it on and of for few times but it makes no difference. Just fyi somebody in the past did some fixes with the electronics and the fuel pump relay is now just above the fuel pump, I hear no sound from the pump with ignition on nor the relay clicking (I didn’t check the fuel pressure as I was willing to do today at the mechanic but I was a bit frustrated so I forgot…). I’m currently very confused and have no idea what to do, every suggestion would be good!
Suggest to post your car’s model year also. Sorry you are having this difficulty, frustrating. My guess, you have a leak in the exhaust system. Allows outside air to hit an o2 sensor, making the computer think more gasoline needs to be injected than the engine actually needs. Wet spark plugs and black exhaust smoke (indicating overly rich mixture) are the result. The leak could be in a section downstream of the O2 sensor. But my guess is you either have a cracked exhaust manifold, or the exhaust manifold gasket needs to be replaced.
Suggest to ask your shop if they know how to confirm this is the problem by inspecting the o2 sensor signals. If your car is OBD II, a fuel trim test could be useful as well. A compression test makes sense too. Post results here for more ideas.
I really don’t think anybody is going to go out of there way to help you when you keep ignoring a very simple request such as WTH is the freaking YEAR of your vehicle??? lol
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Oh yes, sorry, 2000.
Your 2000 model year vehicle uses OBD II technology, and has at least two o2 sensors, before and after the cat. If your o2 sensors are missing or disconnected, that’s the most likely cause of your fuel/air mixture problem. The drivetrain computer uses the sensor signals to set the correct air/fuel ratio.
Thank you for your time and your responses, you did help me a lot understanding what could be wrong with my car, for sure more than my mechanic… I thanked you once but seriously i’m so grateful for your help!!! For these few days I drove my tigra a bit and it does drive much better than before, has more power and it didn’t misfire so far, but starting is still problematic and cel turns on periodically, also I figured out that oil lamp blinks if I brake a bit harder? I hope that can wait because I have some o2 sensors to deal with! Once again thank you and God bless you!
Check the crankcase oil level on the dipstick. If low, top off to “full” mark. If oil is very dark or black, replace engine oil and filter with fresh stuff.
All done, about two months ago, but the oil is a bit over the max line but not over 10% of the capacity, I read somewhere that, that is the borderline for no problems, correct me if i’m wrong
1/4 inch over the “full” mark on the dipstick is usually ok. The oil light turning on during hard braking symptom is somewhat concerning. If I had that problem and oil level was ok and oil in good condition I’d ask my shop to use their shop gauge to check the oil pressure. I wouldn’t wait on this, hoping it will go away by itself. With luck it is just a bad oil pressure sensor or wiring problem.