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Rough Idle after head gasket replacement.

16K views 31 replies 5 participants last post by  dmax 
#1 ·
Hi, I'm new to the site.
I just finished replacing a blown head gasket on my 1995 Sonoma 2.2L (manual trans if that matters).
After re-assembly, I started it and it had a rough idle. I took it for a drive around the block and it had very little power and was stumbling.
I've replaced the head gasket 80,000 miles ago and it started without issue at the time. I think I assembled something incorrectly and would like some help to steer me in the right direction

On disassembly, I labeled the spark plug wires and re-assembled in the same order so I doubt that is an issue but you never know. The ECM isn't throwing up any codes so I don't think I forgot to plug anything in.

My questions are:
1) How do you set the valves on the 2.2? I set them for 0 lash. The manual says to torque the rocker studs (at TDC) at 20 fl lbs (or something close. I don't have my manual handy right now). This doesn't seem right. When I actually torqued them down, they looked like they were just opening the valves (seemingly quite a bit).
I found another website (after I had the problem) that said to set for 0 lash plus 1/2 turn. This seems to make a lot more sense for hydraulic lifters.
2) I just set mine for 0 lash. Would this cause the problem I am experiencing?

I can't remember how I set them the first time I changed the head gasket but it worked.

Thanks in advance. Hope you can help me save time chasing my tail.
-otto
 
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#7 ·
No, I didn't have it checked or resurfaced. All I did was carefully scrape away the old gasket form both the deck and head. Water would run in the cylinder when it was off and a lot of white smoke would come out when re-started. It doesn't appear to be doing that now. I didn't notice a burn in the old gasket when it was apart.

Are these heads known for warping?
 
#9 · (Edited)
yes they are, its an aluminum head and anytime you do a head gasket on an aluminum head engine its pretty much required to have the head resurfaced 90% of the time unless you want to risk it blowing again or even being blown right from the get go witch is what it sounds like has occurred on your engine

i just did the head gasket on mine about a month ago, rather than having my head worked on to save time and to make sure i had no problem i just bought a re manufactured head from American cylinder head in oakland
 
#10 ·
... i just did the head gasket on mine about a month ago, rather than having my head worked on to save time and to make sure i had no problem i just bought a re manufactured head from American cylinder head in oakland
If you don't mind me asking, how much did they charge?

I'm wondering if it's worth it now. The truck has 180,000 mi and something major could happen at any time.
If I decide to part with it, you wouldn't happen to know anyone interested in a new set of tires would you?
 
#12 ·
after tax it ran me about 460 bux, if your head is just warped and not cracked and has never been machined before a machine shop can just mill it down and it will cost not even half that, though at 180k miles idk if you wanna do it even

if i wasn't broke i might be interested in your tries because i could use some new ones but after dumping 1k into my truck fixing stuff while doing the head gasket i cant right now :(
 
#13 ·
oh also these motors often blow gaskets due to overheating even just to say 230 degrees, thats about how hot mine got 2 days before the gasket blew completely, this warped my head for sure and i could tell because all 5 exhaust side head bolts were not very tight compared to the intake side bolts, a sure fire sign that the head is warped
 
#14 ·
Thanks for the info. I noticed the front and back head bolt on the exhaust side were not as tight as the rest but not really lose either. I usually check heads with a straight edge but I don't know where mine went. Besides, the deck and head didn't look that bad

I had a freeze plug leak and all my water went out of the block. There wasn't even a dummy light to tell me that the coolant was gone and the temp gauge hardly moved. I just noticed that the engine was running rough and when I pulled over to check out why, there was no coolant and the unmistakable smell of cooked gaskets. Since I only use synthetic oil, the oil pressure was still good.

She lasted me a decade and 100k miles. I suppose it's time to move on.
 
#15 ·
that sucks, yeah at 180k miles its tough to dump money into an engine unless your up for doing a complete rebuild because you know you will likely get only 20-40k more miles at the most out of the bottom end at that point, mine only has 88k miles and is a 00' and i might even have a rod knock now idk for sure but i think its just piston slap cuz my motor has decent knock when its cold that almost goes away completely once warmed up now :(

imma just drive it and if the knock gets worse ill know its the bottom end untill then it just drives me nuts thats all haha
 
#17 ·
oh i've owned it from 43k miles, done the breaks once, fuel pump once, alternator twice, had to get the abs computer rebuilt, head gasket, radiator (it cracked and thats how my motor overheated slightly and blew its gasket) and it eats starters for lunch almost yearly....

i'm about ready to find a back up ride if things keep up with my truck haha
 
#18 · (Edited)
stop using junk starters. no starter should fail that often.
same thing for the alternators.

get napa's alternators.

avoid autozone parts 100%.
everything I've bought from autozone I've had to return within a year since I put my new engine in. I bought a few of their sensors, and every one of them had to go back.
even the spark plug wires.

I started using advance auto parts because they sell borg warner(BWD) electrical parts that are made in the USA.
so are the spark plug wires they carry.
they also sell good name brand suspension parts such as moog. and monroe shocks etc.
best store around if you ask me.

everything I've ever bought from napa and advance I've never had to return or had problems from it.
 
#19 ·
i never buy parts at autozone, i get all my parts from the same place all the local auto shops get parts from, its not a major chain store and around here when a chain store like kragen or autozone and even napa dont have a part they end up buying from allied auto parts the store i go to because they carry more parts than anyone in my area peroid

also when ever possible i only buy acdelco parts for my truck, on the starter i've tried many different brands from cheapo ones to delco and the solenoid always gets fried from the heat of the exhaust down pipe sooner or later because the first time it went out i lost my heat shield that should be on it to protect it, have also tried using the fiberglass starter heat wrap but it just prolonged its death another 6 or so months i'd say

maybe before the next time it goes out ill hit the junkyards and see if i can get that heat shield but otherwise i know my starter will go out like clockwork at about a year after its installed and its not that hard to replace it when it happens :)
 
#21 · (Edited)
its because its missing the solenoid heat shield, i couldn't get it back on the first time i did the starter because you gota remove the exhaust downpipe from the manifold to get it in then i lost it before the 1st replacement died

its for sure the reason why they go out all the time :)

the good news though is when it happens i can still get it to start, it just becomes very hard to start after it gets hot from driving so i'm still able to go to work etc. just gotta let the starter cool down for 2-4 hours before it will work normally again haha
 
#22 ·
Well, I'm a glutton for punishment. I pulled off the head this weekend and checked with a straight edge. It had over .007" across the head between the #2 and #3 cylinder. At one point lengthwise diagonal, it has almost .009". I guess one of tomorrow's activities will be to phone around for a machine shop.
 
#23 · (Edited)
For those still following this saga, I dropped the head off at the machinist yesterday. He noticed some funny discolorations and said that they are probably cracks but he will pressure check to make sure. It's a common occurrence with "styrofoam" type heads like ours. The castings look like styrofoam meaning (I believe) they are made from a lost foam casting technique giving them that texture.

In any event, he called this morning to tell me that he found 3 cracks so far and that the head is no good. I will have to buy a replacement.
 
#25 ·
that sucks man, one of the reasons why i just decided to get a re manufactured head rather than spend money just to find out its no good :(


really though with the mileage you got on that motor now your prolly best off to get a reman head and rebuild the engine unless you just wanna throw the least amount of money at it to get it going for another 20-40k at most i'd say
 
#27 ·
Yah, that's the plan. I'm going to fix it and shop around for another vehicle. The paint is all faded like every 1995 I've seen around so it's hardly worth what I've put into it lately.
The machine shop guy here was quite reasonable.
$15 to clean
$40 to pressure check
$40 to mill
$20 to install new seals (I had them laying around)
Of course all he did was clean and check so That's what he's charging for.
A replacement will cost around $400.
Thanks for your help dmax
 
#26 ·
Lol, this thread is still being discussed. I had a feeling i already read something way similar to this post. Same 1...Lmao!
GOOD LUCK THOUGH!
 
#29 ·
Well, I just installed new head and although it runs better it's still rough at idle and has minimum power throughout the RPM range. It appears to "hunt" as well. The idle varies in RPM and sometimes it sounds smooth other times it sounds rough. It also makes noise when running rough but no noise when smooth.
 
#31 ·
OK, I've been busy so this has taken a lot longer than it should have but I replaced the plugs last night and it is finally running good. Of course with my recent luck, the alternator stopped working. It must have got cooked when the engine overheated. Anyhow, I replaced it this morning and was able to drive it into work (1/2 hour drive) without incident.

Thanks to everyone for your help.
 
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