|
|
Post by moofus02 on Dec 3, 2015 7:39:07 GMT -5
For all the gurus out there. I bought the wife a suburban a few weeks ago. 1999 with 192k and 5.7 vortec. She blew a rear heater hose in town and the temp spiked to 240 plus before she shut it off. I fixed the hose and pressure tested the system took it for a ride and it was shaking bad like a cross fire (motor got sprayed with coolant on right side) I changed the wires and that helped but it is still doing it. Coolant level is stable I think it is jumping the plug insulators. I'm going to put a set of plugs in it and check for a cracked head. Anyone have any ideas?
|
|
|
|
Post by 90GTVert on Dec 3, 2015 8:57:31 GMT -5
Check engine light on? If so, what codes do you get?
If you change the plugs, make sure you inspect each one for signs of anything awry inside of each cylinder.
|
|
|
|
Post by derbiman on Dec 3, 2015 12:33:36 GMT -5
Sounds like a possible blown head gasket. Like Brent said,check the plugs and also check the oil to see if coolant got in the crankcase and vice versa check for oil in the coolant. If one or more plugs are wet,then it is definately a head or head gasket.
|
|
|
|
Post by derbiman on Dec 3, 2015 12:40:45 GMT -5
Also, check the exhaust pipe for steam and the odor of antifreeze.
|
|
|
|
Post by niz76 on Dec 3, 2015 18:58:35 GMT -5
I used to have a little 4 cylinder hatchback Ford Rustang (when I lived in MI) that would shimmy and shake and shutter everytime it rained apparently due to moisture in the distributor cap. After driving it hard for like 10-15 minutes it would dry up and act normal. I have no idea if this could be the case with your Suburban... I understand these little scoots better than cars! lol
|
|
|
|
Post by 2stroked on Dec 3, 2015 20:15:44 GMT -5
A lesser known way to check for a blown head gasket, is with a circuit tester probe.
Clamp the negative alligator clip to the ground on the battery, start the engine, with the radiator cap off. Then hold the probe in the coolant, without touching the metal. If there is a bad gasket, the voltage from the lost spark will sometimes ( pretty often ) travel through the coolant, lighting the probe.
This wont work every time, but it beats a tear down search mission.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 3, 2015 21:20:07 GMT -5
it could be a bad head gasket or maybe something warped from the heat (unlikely). I overheated my chevy Aveo when the thermostat failed while driving and I pegged out the gauge. the temp isn't marked on the gauge but I immediately shut it off upon noticing it. couldn't have been pegged for more than 20 seconds because im pretty good at keeping watch on the gauges. after I got it stopped I turned the key back on and plugged in my OBD reader I had with me and the coolant temp was at 261degrees F. it boiled and bubbled for quite a while after io shut it off but once the thermostat was replaced it ran fine with no damage (and still does). when I saw it was that hot I thought the head probably warped or the gasket was ruined but not the case. this is a 4 cylinder BTW.
I really don't think the gasket would blow from being 240 degrees but weirder things have happened. did any coolant get on the dist cap? I really don't think the head would crack from only 240 degrees either.
**EDIT** I didn't think about that it was probably run at least partially dry from the hose busting. it may have warped or cracked it because of the uneven heat because of the lack of coolant. maybe you could get a rebuilt/refurbished head or one from the junkyard off a vehicle that came in running from being rear ended?
|
|
|
|
Post by ryan_ott on Dec 3, 2015 21:59:00 GMT -5
When checking for coolant in oil do it after sitting when motor is cold. Oil floats on coolant and coolant if present will come out first when draining.
|
|
|
|
Post by moofus02 on Dec 4, 2015 2:01:32 GMT -5
Thanks the coolant level hasn't changed since I put it back togather. Wires helped a cap and plugs might fix it. There was coolant sprayed everywhere on the right side. It really acts like a stray spark issue. It might take me a day or so to get time to work on it again
|
|
|
|
Post by thatcrazyguy on Dec 4, 2015 20:02:49 GMT -5
Whenever I've had to replace heater core hose it let to replacing the head gasket, check that out and inspect the whole top side while your at it. Also drain coolant and replace as their may be exhaust fumes ran back through the coolant.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Dec 4, 2015 23:49:24 GMT -5
Did you bleed the system correctly? My old minivan has like 4 places I have to bleed air from in the coolant system after a radiator flush or any other task that involves draining and adding coolant. I found out the hard way, even though my van is a 1995, that if you do not get all of that air out, it drives the sensors wild. You have the coolant sensor, then the Map sensor, etc, etc. My engine was running as if it was only hitting on 3 of the 6 cylinders, but, turns out the temp sensor was telling the computer that the engine it was hot, when it was not and the mixture was way too lean.
Just an idea, might not be related to your situation.
Bill
|
|
|
|
Post by derbiman on Dec 5, 2015 15:15:18 GMT -5
I miss the days way back when you could work on simple things that didn't involve computers or sensors or highly sophisticated electronics. I used to be able to work on my 1973 Chevy truck engine in the rain because there was enough room for me to crawl up in the engine compartment and pull the hood down. Try doing that on a modern vehicle. Lol
|
|
|
|
Post by FrankenMech on Dec 6, 2015 20:18:10 GMT -5
Engine coolant acts like a resistor to provide a path to ground everywhere the coolant has touched. It will ruin plugs, wires, coils, anything high voltage. There is absolutely no way to clean the coolant off. Once the coolant film flashes over it leaves permanent carbon tracks. The only solution is to replace everything in the secondary ignition system that has been touched by coolant. Moisture in cold weather will aggravate the problem.
|
|
|
|
Post by moofus02 on Dec 7, 2015 3:14:43 GMT -5
Plugs wires cap and rotor plus changing 2 more hoses that were leaking no matter what I did seems to have cured it. Thanks guys
|
|
|
|
Post by Corrosion on Dec 7, 2015 5:56:17 GMT -5
with the engine cold. fill radiator to the tippy top. replace cap. Run the motor for 20 min. watch the coolant bottle, particularly where the overflow hose is connected. usually if the cylinder head gasket has a compression leaking, it will bubble air out the coolant over flow hose, at first just few, then a slow steady stream air will ensue.
If blown between cylinders, it will show up in a compression test, as 2 cylinders next to each other, of equal & low psi.
This type of fail will cause the cross / miss-fire. but not show bubbles in the reserve tank. it is also possible you have sticking valves, this will show up in a cylinder leak-down test as an intake valve leak or exhaust valve leak.
If you are lucky, use some "Gunk- Valve-medic". it has worked for me often, freeing-up a sticking valve intake. the early vortec,s. had tight valve to stems clearance / problems, and did this often. Some times the intake valves would strike the piston and bend the valve. if that, it will show up in a cylinder leak-down test. You need a decent sized compressor & and a "leak-down tester" to do a proper leak down test.
A gas emission, 4 gas analyzer, sample the air in the coolant bottle. it will pick show up as HC & CO in the air space, in the coolant bottle. (don't get any coolant in the tester.) it will also show high HC on a lean firing / valve sticking type cylinder misfire.
|
|
