Emissions fail - high hydrocarbons in exhaust

[DaraSue]

Drove it home today (surface roads, about 8 miles), temp stayed normal (around the unmarked white line) but I had the A/C on the whole way. When I let it idle after arriving at home, it got up to just about the 220 line without the fans coming on, at which point I gave up and shut it off.

Next week I'll try bleeding it and see if that helps. Ryan F (hippieman9 on here) sent me some instructions so hopefully I'll make less of a mess of it than I did last time.

[opethmike]

One thing I do when bleeding the coolant on rear & mid-engine cars is that I back the rear wheels up on ramps, and then let the car sit overnight. The hope is that with the rear higher than normal that the air pockets will be encouraged to collect at the bleeder screw.

[David T]

No need to raise the rear of the car. Just buy or rent a coolant system pressure tester. Pump it up and let the air out at the bleeder over the thermostat and loosen the small hose on the top, right side of the radiator til you get all of the air out. When you finish you should wind up with the header tank 1/2 full cold. Any air still in the system will work it's way out unless you have leaks.

[DaraSue]

Already got a pressure tester (bought it on my way home when I first got the car). With the tester I don't need to have the car running to bleed it?

I've driven to and from work a few times, twice during the day with the A/C on (outside temp 80-90F), once in the morning with A/C off (temp 65-70F), once late pm with A/C off (temp 90-95F)* and twice at night, once with the heater on, once with it off, both times probably 60-70F. Temperature was normal, hovering around the unmarked line, every time. If there's something wrong with my system, I think maybe it could have been that way for months and I just never had occasion to notice until I idled it for prolonged periods?

*I had a 30+ mph headwind for this one though, so that may have skewed the results.

[David T]

The motor does not run while you bleed the cooling system with a pressure tester. Don't pump over 15 psi, 10 is all you really need. Before you start, the header tank should be slightly more than 1/2 full and when you finish you should have to add a little to get it back to 1/2 full cold. if you find you have a hard time getting all of the air out, make sure the thermostat has a "jiggle pin" so air can bypass it when it is closed. If it doesn't, drill a 1/16" hole in it.

[Rich]

Already got a pressure tester (bought it on my way home when I first got the car). With the tester I don't need to have the car running to bleed it?

I've driven to and from work a few times, twice during the day with the A/C on (outside temp 80-90F), once in the morning with A/C off (temp 65-70F), once late pm with A/C off (temp 90-95F)* and twice at night, once with the heater on, once with it off, both times probably 60-70F. Temperature was normal, hovering around the unmarked line, every time. If there's something wrong with my system, I think maybe it could have been that way for months and I just never had occasion to notice until I idled it for prolonged periods?

It's more than likely the system could have had some air in the radiator and/or the engine all this time.

Sounds like you have the components sorted out. Since you do not know the system is bled then assume it isn't.

Bleeding the cooling system is one of the easiest and most important jobs DeLorean. It needs to be done - and done right, which means doing it at both ends of the car - every time coolant is drained/changed. New owners or owners who are not sure if there's air in the system should check/bleed it to be sure.

As David T. notes, if there was air in the system then the coolant level will drop in the header tank after the bleeding is done. That's one way you will know it needed to be bled. And if your fans-won't-start-at-expected-gauge-temp-during-long-idle problem goes away after you fully bleed it that's another way you will know.

[DaraSue]

Well, I tried the pressure tester method of bleeding and it did bleed a fair amount of air, but the fans still aren't coming on. I let it get one or two needle-widths above the 220 line this time, and nothing. This was after driving about 8 miles on surface roads in rush hour traffic. It had crept up close to the 220 line during the drive but then dropped back down to about midwaybetween the 220 and the unmarked white line, but I didn't actually hear the fans come on so it may have just been because we got moving at a decent speed again.

The mechanic said he bled it too after verifying that the otterstat seal was holding and they came on around 212-225. He said he checked the temp at the pipe by the otterstat and he thought my gauge read about 15 low, but when I used my own thermometer it looked like it was pretty accurate (although mine's from Wal-Mart so maybe it isn't the greatest). Arrrgh. I guess I need to try bleeding it with the engine running next?

[Rich]

Well, I tried the pressure tester method of bleeding and it did bleed a fair amount of air, but the fans still aren't coming on...... Arrrgh. I guess I need to try bleeding it with the engine running next?

More info would be good to have.

From where did it bleed a fair amount of air? Upper right rad hose (the small hose/nipple?) or the bleeder screw on the pump housing?

Getting air out of each of those spots is important. One of them is not enough...

Because there is a bleeder screw at the engine and not one at the radiator many people, including mechanics, only pay attention to the engine side...

Agreeing with David T. that running the engine isn't important to proper coolant bleeding. The car can be bled at rest.

And the rad can be bled without pressure. Gravity is enough for that end.

[DaraSue]

More info would be good to have.

From where did it bleed a fair amount of air? Upper right rad hose (the small hose/nipple?) or the bleeder screw on the pump housing?

Getting air out of each of those spots is important. One of them is not enough...

Because there is a bleeder screw at the engine and not one at the radiator many people, including mechanics, only pay attention to the engine side...

Agreeing with David T. that running the engine isn't important to proper coolant bleeding. The car can be bled at rest.

And the rad can be bled without pressure. Gravity is enough for that end.

I loosened the radiator hose first (the small one on the upper right where it attaches to the radiator), and that seemed to lose the most air, there were several seconds where I could hear it hissing out before it started squirting out antifreeze. I did the bleeder screw on the thermostat housing second, it seemed to bleed antifreeze fairly quickly. I had parked the car nose-down for a couple hours first, should I have tried to keep it level? My driveway slants down, my garage slants slightly up.

Also, IDK if this is relevant to my original problem, but while I was poking around in the fusebox after the last idle test, I noticed my lambda relay was really hot, like too hot to touch. Is that normal?

[opethmike]

No, you definitely want that rear end up.