Hello,

My inspection expires the end of the month, so I brought the car in for an inspection. Inspections are every 2 years here in RI. I have the paperwork for the last inspection, which was 2 years and 2,500 miles ago.

Here are the readings for the inspection:

7/19/2011:
--------------------------------------------
HC PPM (IDLE): 10 [LIMIT: 220]
HC PPM (2500 RPM): 11 [LIMIT: 220]

CO % (IDLE): 0.01 [LIMIT: 1.2%]
CO % (2500 RPM): 0.01 [LIMIT: 1.2%]


7/17/2013
--------------------------------------------
HC PPM (IDLE): 217 [LIMIT: 220]
HC PPM (2500 RPM): 210 [LIMIT: 220]

CO % (IDLE): 0.62 [LIMIT: 1.2%]
CO % (2500 RPM): 0.12 [LIMIT: 1.2%]


Why such a HUGE difference in readings? Any ideas what to look at first? I have a slight shake at idle, and the car does burn a little oil. The car was hot when I brought it in, and only sat 10 minutes before it was tested. I had unplugged the battery yesterday to install the new radio, but drove the car at least 20 miles since then.

Thanks,
Nick

 

Could be the egr port in the intake manifold - notorious for carboning up. Will cause rich running and high NOX readings. Usually accessed from under the car(!!) as it is located on the underside of the intake manifold.
An easier way to get at it is to remove the idle valve on top of the manifold. Mine was completely blocked from short trips of in-town running, dug out the carbon and she ran like a bird again.

 

Sounds like you would benefit from a Terraclean treatment or similar?

Check out Terraclean

 

NTL, 2500 miles in 2 1/2 years is the reason for the difference.

Likely everything will be gummed up, or even corroded.

Using oil, hardly surprising on such an unused vehicle.

You certainly need to change all fluids inc fuel tank contents, and drive the thing for a respectable distance. (hard)

You might even want to shake out the mice nest in the air box, they do gum up the works. (it's a fur thing on air flow).

 

+1

An 'Italian Tune Up' is required.

Graham

 

They've had the car 18 years and always drove very few miles per year. I'd guess the past emissions test would be just as bad if that's the cause, but it was outstanding.

The car will definitely see the road more often now that it's replacing my daily driver. At least a 4x increase in yearly mileage, and it'll be driven year round.

Plugs were last changed 13 years ago (about 18k miles ago) at the dealer. Wires look original. I'm going to start by pulling the plugs to check them, and measuring the resistance of the plug wires against the factory specs. I'll install a new distributor cap and rotor as well.

One thing at a time.

Thanks,
Nick

 

You don't say what year model 3.6/4.0 you have. I found when doing emissions testing for MO that if the Jag did not have regular oil changes and had a different oil than the 20/50 they failed emissions on a regular basis. A lot of customers put 10/40 in and when weather warmed and wanted testing the lighter oil actually left residue in the manifold and was detected by BAR90 and failed. Once changing to spec oil vehicle passed immediately. This was in the early 90s.

 

Interesting Jagfixer, thanks for that info.

The car is running 10/40 right now. Maybe the 20/50 will also help a little with oil consumption. It has been in the lower to upper 90s all this week. That might just have something to do with it.

Would 20/50 be okay for Rhode Island winters, January and February average temps are in the high 20's to mid 30's.

Thanks,
Nick

 

20/50W factory spec. Use for inspection and for winters. When below 30 deg. use 10/40W. That's what I use personally and for customers. Just change before emission testing or warm weather whichever comes first.

 

Drained the oil and refilled with Castrol GTX 20W50. Got the oil filter and drain plug gasket at the Dealer, along with a bottle of HSMO to top up the reservoir. Oil pressure when cold starting jumps right up to 7 on the gauge. With the engine idling while at operating temperature, it stays at 3.

Also replaced the spark plugs with new Champion RC9YC's, and replaced the original Lucas distributor cap and rotor. I'm going to test the resistance of the wire set to see if they need to be replaced.

There was a bit of oil in each spark plug well except #1, Maybe about half an inch up on the bottom of the plug wire boots. I removed the plugs one at a time and marked the cylinder they came out of. I'll post pictures tomorrow. They were quite dirty, full of ash-like deposits on the ground electrode.

New plugs helped the occasional miss when idling.

 

Just an update:

Greased all four Universal Joints on the drive shafts. I could hear them crackling as the new grease pushed out the old!

Also drained and refilled the differential. Used Royal Purple 75W90 oil. The oil in there was pretty clear and yellow as it drained out. Only a tiny bit of fuzz on the magnetic drain plug. No noise before, but I want to make sure it stays that way.

Also noticed the car did have the hydraulic shocks removed and replaced with conventional units. There's a bleeder screw on the valve assembly under the hood where the feed line to the struts would attach. I guess it's one less thing to break.