HG replacement failed, need ideas

[turbocruiser]

As everyone's already stated, I think its too soon to tell the outcome here. You need to slowly take the temps up and let it run itself clean from the combustion chamber to the exhaust's exit. Mountain High Performance is awesome, I simply cannot imagine them missing any cracks around the head, now the block could be cracked BUT I think that the process of elimination dictates you do the temp thing first. Ohh, in case it is indeed air in the system, try parking the rig hood up on some slope with the rad cap off for a few minutes. HTH.

 

[landtank]

everyone has already said it but I'll also say that it's most likely fine. Take it out on the road and drive it. Just watch the temp closely and drive it some more. It will just last that much longer if all you do is let it idle.

 

[lagwagon]

What people keep forgetting to do is a differential pressure or leakdown test. This will tell you if you have a bad valve, bad rings, coolant leaks. It will not tell you the headgasket or block is bad for the most part, but it will isolate the cylinder or cylinders. This should be done before anything is taken apart. What it also will not show is a bent rod from hydrolock. I have seen spark plugs and injectors blown apart do to hydrolock. That said I think you should run it a while as I have run some vehicle for 20 mins. plus and still had smoke. You could be burning off carbon, coolant, brakeclean, ect. I wish you the best of luck. There is nothing more difficult than a job done twice, at least in mechanics.

 

[97fortieth4me]

What people keep forgetting to do is a differential pressure or leakdown test. This will tell you if you have a bad valve, bad rings, coolant leaks. It will not tell you the headgasket or block is bad for the most part, but it will isolate the cylinder or cylinders.

Fortunately, we did that with mine and it confirmed that there was a leak in the #6 cylinder. Pressure in the other cylinders were good. Thanks God from friends who know what they're doing.

Toyota "red" coolant was very visible down in the #6 spark plug hole, BTW.

 

[landtank]

When I did my HG it started right up and drove fine. Parked it at the top of the driveway and came in for a couple of celebratory beers and about 10 minutes later my wife points out a huge oil puddle under the truck.

First thought was I screw the HG. Nope just screwed the valve cover gasket.

 

[e9999]

mine never runs rough after the battery was disconnected....

 

[FrankTorres]

Just a quick reply... but only letting it idle for about 5 minutes is NOT enough time to completly burn off coolant in the exhaust like Doug mentioned.
My 7mge in my Supra smoked for 25 minutes after I did a blown head gasket repair.

Driving it till the exhaust heats up fully should remedy the smoke.

for the miss, I would look at ignition wires or an injector connector not plugged in or something.

..anyway good luck and lots of us have been where you are.

 

[zukatude]

First off let me thank everybody for their helpful replies, kudos to this forum

I am now much more optomistic that its actually ok. Here's what happened this evening.

Checking back over the ignition and distributor timing, I finally remembered that while taking the air cleaner assembly apart, I mistakenly disconnected the mass air flow connector wrong. Rather than try patiently to remove the stubborn connector correctly, I went ahead and unscrewed the connector body from the housing, and pulled the connector out. Well, its not designed to come apart this way and I ripped out some of the soldered leads. At the time I thought they were spring loaded and just shoved it back in.

So this evening I cut the silicone seal off the top and repaired the solder joints on the pc board inside. This immediately took care of the miss and stumble. Helps to actually have a working MAF

I continued to let it idle and observed. The bubbling in the coolant overflow had disappeared. It never got hot. It was producing less tailpipe steam but since it was about 38 degrees outside I guess it will still make some steam. The water dripping from the tailpipe is clear. Before the HG replacement it actually dripped green coolant out the tailpipe (scarry). It really runs so smooth and quiet, rock steady idle at 650 rpm, and revs up very easily. Prior to the HG replacement, it was very obvious that only 5 cylinders were doing anything. If the HG is still leaking, it sure does run good. The only indicator left that anything could be wrong is the oil cap is collecting water droplets just like before. I'm crossing my fingers that its just left over water in the crankcase.

If I had somebody to help me put the hood on, I'd take it for a spin, but it will have to wait until I can get my neighbors help tomorrow.

Thanks again for everybody's help, you guys rock!

-Paul in Windsor, Colorado

P.S. I still think you guys get to obsessive about stuff like painting your wheels, powercoating engine parts, and otherwise fufu projects

 

[stevek]

Good to hear!

 

[semlin]

paul, glad to hear it is working itself out. just to echo everyone else, I had big time concerns after my h/g job. had the dizzy off a tooth, weird noises at initial start up, coolant vapour lock issues and other little things. It took a while to work them out but it has been running great now for some months. so chances are you are fine!

 

[RavenTai]

 

[Rookie2]

Just for the record, I was going to mention yesterday to make sure the MAF is connected back up, but I got busy and had to run out.

 

[NaterGator]

Haha, I don't want to monday morning quarterback either, but I was gonna say that it now sounds like an emissions system problem rather than HG problem.

The rough idle and stumbling on accel sounded like fouled O2 sensors or a bad MAF. I was going to suggest driving the truck to the nearest shop and getting the codes pulled, and if possible live data collected while the truck runs.

With all the crap that has gone through your exhaust system, you may want to keep an eye on those O2 sensors, they're probably feeling pretty abused.


Glad you got it worked out though and it turned out to be simple!

 

[Gumby]

 

[wsdavies]

On a side note, did you replace the O2 sensors?

 

[zukatude]

On a side note, did you replace the O2 sensors?

No sir, I did not. I will do some research to find out if narrow band O2 sensors can be fouled by coolant.

Edit: a quick web check indicates that O2 sensors can indeed be damaged by the silicates in some kinds of antifreeze. Since I was running prestone green, and it does contain silicates (rather than toyota red which I believe does not), I should test the O2 sensors now.

-Paul