I think testing the coolant with a combustion gas sniffer would be a lot quicker than checking compression on all 6 cylinders. I've done that before and it would take at least an hour, especially if the mechanic hasn't dug down into the driver's side of the engine very often. Just my opinion, but yeah I would think you could check compression to figure out which of the two heads has a leak after you know there is combustion gas in the coolant. Andy --- In dmcnews@xxxxxxxxxxxxxxx, gmfm1@... wrote: > > I haven't seen anyone suggest a compression test on the cylinders to see if the head gasket is blown. Any reason you wouldn't do that to check the head gaskets? > > Thanks, > Gary Masie > > ----- Original Message ----- > From: jedimasterglenn > Date: Sunday, April 15, 2012 9:22 pm > Subject: [DML] Overheating, idle speed and stalling issues > To: dmcnews@xxxxxxxxxxxxxxx > > > Need some advice (or a DeLorean mechanic to open shop in MA!!) > > on what to try next for what I think are 3 separate issues: > > > > 1. I recently replaced my entire cooling system: radiator, > > fans & fan assembly, new water pump & thermostat, coolant > > bottle, and all the hoses except the ones to the heater core > > (all of them...even the small ones under the car). I added a > > valve (petcock) near the radiator to make bleeding easier. I > > have NOT put in any kind of self-bleeder system. I've bled the > > system several times per the instructions here > > (http://delorean2109.blogspot.com/2008/08/burping-your-new- > > delorean-baby.html). But every time I bleed it, I find air. I > > bleed it until there is no air. > > > > After bleeding, if I start it cold and leave it running/idling, > > it stays around 150F. When driving, temp stays consistent > > around 180F, but if I come to a stop for longer than a couple > > mins, the temp creeps up and will continue past 220. For > > example, I drove for an hour on back roads and highway today and > > it ran around 180F the entire drive). But when I got home and > > left it idling in the driveway, the temp started to rise as > > described. The new fans do work. I jumped them to test and > > also heard them come on at a bit less than 200F. I noticed they > > shut off when the temp went above 220...which I suspect is air > > causing an issue. And of course, I didn't let the temp go any > > higher and shut the car off. There are no coolant leaks that I > > can see and the coolant level holds at where I fill it (about 1 > > inch over the main opening in one of the new stainless tanks). > > > > I have the fans wired to pull the air through the radiator from > > front of the car to back vs push...which I think is > > right...right? > > > > 2. Prior to the cooling system replacement and since, my idle > > speed has been rough. When I first start the car, the idle is > > good, hovering just below 1000rpms. But as it warms up, it > > starts to seek up and down between 800-1100rpms. I've checked > > the air flow meter inlet & intake manifold seals for leaks (I > > replaced all the manifold seals when I did the cooling system). > > I think these are fine. > > > > 3. And rounding out my collection of headaches is what I like > > to call the "downshift-stall mystery". I have a manual > > transmission. Again, this was happening prior to the cooling > > system overhaul. It doesn't happen consistently, but when it > > does it's always when stepping on the clutch and always at low > > speed, when downshifting(usually from 3rd to 2nd). I step on > > the clutch and the rpms abruptly drop to zero or close to it. > > Before I have time to shift gears, the car has stalled. > > Sometimes it shifts fine and other times it starts to stall but > > recovers. It idles without stalling, but as noted in #2, the > > idle seeks. Only thing I've tried is adjusting the idle speed > > microswitch, but to no avail. I have the microswitch set so > > that the throttle striker just barely trips the switch when the > > striker is at rest position. > > > > Thanks, > > Glenn > > 5391 > > > > > > > [Non-text portions of this message have been removed] > ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: dmcnews-digest@xxxxxxxxxxxxxxx dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/