Hey wrench wranglers, what are problem possibilities when engine light icon stays on after ignition? Checked oil, coolant, belts. etc. It's just at 50k miles. I know I'll prob need to take it in but I just wanted to be prepared for diagnosis. Tks.

 

I've moved your question from General Tech Help to XK8/XKR forum. This is the place to post technical questions about your model.

There's many error codes that will illuminate the MIL. First step is to have the codes read to see which of them has triggered yours.

Graham

 

Read the codes.

 

As JAGV8 said, you have to read the codes or let a shop do this...

If ONLY the CEL-Light is illuminated and you get no further message in the display, it should be, from my experience, a not so serious error.

e.g. i had a failed heater-coil of one downstream Oxy-Sensor. As these are only used for monitoring, the engine goes NOT into 'restricted performance'.

Nevertheless you should let it be checked as soon as possible...

Greetings,
Wolf

 

They're usually used to fine trim the fuel trims too (as per the workshop manual etc)...

 

Thanks to all. Got a reader. Code is P0171 "System too lean Bank1". Is culprit likely O2 sensor? If so is that a DIY fix? Tks

 

Doubtful, as there are specific codes for those.

Have a hunt through other threads with that code or P0174 and what people did next.

 

Looks like there are a million scenarios for P0171. Code reader showed "OK" for all I/M readiness monitors incl O2's. Did easy stufff like visually cking vacuum hoses, new air cleaner, checking MAF and cleaning sensor. Found that one of the 'Alien' resonating tubes coming off the MAF was rubbing on the shock housing. Couldn't see a hole but taped it anyway and cemented a piece of rubber between tube and shock housing as cushion. Disconnected neg battery terminal for reset overnight. We'll see tomorrow.

 

Like a wart, CEL still there. Have not tried to erase it with EBDII reader. Any hazard in that? Will it erase any manufacturer codes?
Tks

 

Check fuel trims. Do a smoke test if any signs of an air/vacuum leak.

 

Tks JagV8. Will see if my Walmart OBD will show fuel trim%. After I've made repairs, is it OK to erase P0171 code or will I lose other info ?
Tks

 

Erase if you like but if it's fixed the MIL will go off anyway after 3 warm ups. Note: erasing would also clear all the OBD monitors which need to re-set for most state inspections and would be a major hassle if they didn't.

 

Big thanks. That's the type of info a novice needs. Last Q (probably not): where best to connect a smoke machine on my 05 XKR?

 

No idea, don't have the car.

 

Ok, anyone with an XKR know the best vacuum hose to push the smoke through?
Tks

 

I would recommend you get an ELM327 off of eBay or Amazon for a few $. Then get a phone app for a few $ more (I use Torque Pro). This will give you the fuel trims. That code needs to be understood and being tripped when there is too much air leaking in, outside of what is measured by the air flow meter. There can be multiple causes. As you fix things, you can see the short term trims going negative, and the long term trims eventually going down. The code is tripped when the system adds 25% of fuel to what is measured, which is a lot. Once you have the tool, start with the fuel trims at idle.

You need to "go around" and patch up all the leaks. Check all the hoses to the heads, one by one. Get a good selection of o-rings (Harbor Freight has great cheap kits). Check the oil dip stick. Check the EGR pipe, too, the bellows crack with age. Check the big air intake pipe for cracks. If you see oil, there is probably an air leak, too. Check the PCV valve. From memory, P0171 is bank 1, passenger side in the US, so concentrate on everything on that side. Also check the fuel trims on the driver side. The goal is to bring both long term trims in the low single digits at idle. Anything in the teens and above, even if corrected by the trims, really makes the engine run less than great. Take it as a game where you pursue the leaks for the purpose of lowering the trims. Don't assume there is just one leak for this code. With age, there is typically a bunch of small leaks. Most should be cheap to fix.

Best of luck, keep us posted.

 

Thanks fmertz. Been using a cheap OBDII meter. Shows EGR, O2 sensors, EVAP, Misfire, etc all OK. Car runs great, no problems. Engine bay is pristine, just 50k miles. Just a CEL, P0171 Lean Bank 1. Trim snapshot shows Short at 5.5% and Long at 18.8% (strangely for both banks) but I don't think I can get real time Trim at idle and 2500 rpm on my OBD cheapie.
So I'll get the OBD u suggested to get real time Trim.
In mean time have done easy stuff: cleaned MAF sensor, checked for leaks with carb cleaner, ordered new gas cap (seem to remember an earlier Emmission Inspection where the tech mentioned something abt the cap). Been reading up on how to do smoke test which is next if cap replacement doesn't help.

 

Your tool is good enough if you can get that.

That 18.8% is way too high. Should be brought back to the low single digits, say, less than 5%.

If it is like that on both sides, then double check the common path, up to the throttle body. Even on a new looking car, these cheap o-rings are well over 10 years old, exposed to oil and heat cycles. You need to go around and replace them. It's not hard, and does not take that much time. Can be done in multiple installments, too.

Best of luck, keep us posted.

 

Thanks again. I'm looking around the common path to throttle body and just don't see many O rings to replace. Are they under the MAF assembly. I looked at my JTIS and couldn't find a schematic showing O rings. Any suggestions?

 

Or have it smoke tested for leaks.