Nissan Repair: 1996 Nissan Altima, intake manifold gasket, nissan altima

Question
QUESTION: Hi Calvin,

The system wouldn't let me do another follow-up in that thread, so I had to start a new one.

I don't think I've run the engine long enough for it to get hot per se, but I have run it long enough to get it up to temperature. I wanted to test the heater in. No Heat after a new thermostat. No big deal on that right now though. It may just be a bad one unless you have other ideas.

I suppose it's possible, though I don't know how, that the head gasket may have gotten damaged when putting it in. They're pretty tough. At least tougher than the average gasket anyway.

Kind of makes sense on the compression though. I was reading somewhere about the intake manifold gasket going bad pretty regular in these engines. Not sure that would lower the compression though. I read that that would also cause the rough idle and all that, but never seen anyone say it affected the compression though.

One thing that is for sure, is the fact that compression is definitely down in that cylinder. Deep down inside, though my brain has refused to admit it yet, I kind of thought of the head gasket again too.

I'd kind of like to do all the checking possible though before doing that a second time. Though by now, I think it could go much faster LOL.

Anyhow, Interested to see what you might suggest now, but I think I'm starting to get the mind set to pull that head again. The compression test indicates that anyway.

ANSWER: Hi John -

I know how you feel. During my career I have had to do a few head gaskets over again, not a good feeling.

It is hard to say what the best thing for you to do at this point, as I wish I was there to actually touch and feel the vehicle, so to speak.

The intake manifold gasket has nothing to do with compression, although a leaking gasket could and will definitely affect the idle, and go away at higher RPMs. It will not cause the engine to race and ramp up RPM as you described, though.

Another thing I wanted to ask you is if the head was resurfaced when the gasket was replaced. This is a must, as more times than not, the gasket goes because the head was warped and not true. Makes all the difference in the world.

Let me know -
mahalo
calvin

---------- FOLLOW-UP ----------

QUESTION: Well, I took the head off today again. The gasket was messed up. It didn't actually blow so to speak. It looks more like I did something in putting it all back together.

I'm going to explain what I did so the readers will hopefully NOT duplicate what I did.

First, to answer your question, THIS TIME I'm taking the head in for surfacing. The other time I didn't because I used a level on it to check for warping as the book suggested, and it seemed fine. Seeming nothing. This time it goes to a machine shop for leveling.

Now, here's the way I did it. When I took the head off, I had to get that heavy thing off by myself. Naturally I wasn't worried about the old gasket, but I did excercise concern when putting things back together, BUT NOT ENOUGH obviously. I do recall "wiggling" the head a little to get it into place when reinstalling. That combined with maneuvering the head in place to begin with, damaged an otherwise new head gasket, and I was doomed before I even finished putting the motor back together.

So, with Calvins help folks, I pinpointed the problem to a bad head gasket DESPITE the fact I had just finished replacing one.

The head gasket looks like I raked it in a couple of different places, for someone with limited income right now, this is a bit of an expensive mistake. $40+ would be more useful elsewhere for sure.

Anyway, a valuable lesson learned. The head will be resurfaced before it goes back on, and when it does go back on, it won't be until I have someone here who can help me lift it back on.

For those who are gaining information from this, especially the "backyard" mechanic types, if you tear the engine down this far, you may as well go ahead and check everything that could possibly go wrong or that may need a new gasket while you have it torn apart.

In my case, this is the second time in 2 weeks I've had this apart. If I would have had the help lifting it back in like I should have, I may not be going through this again. Next time I will wait for the help.

Calvin, I thank you kindly for your assistance. As things progressed, I kind of figured the head gasket, but refused to allow myself to believe. It was indeed though, so, back to the drawing board, and while it did go a little faster coming aprt since I knew where everything was that had to come off, it will go back together slower ;)

Answer
Hi John -

Thanks for the evaluation and the kudos. I am sorry that you have to do a double job. I certainly know how that feels. But, I am glad that the problem was found.

Yes, very important to take that head to a machine shop, a level won't do the trick when a thousandths of an inch could cause failure.

Don't forget the proper tightening sequence, from the center of the head out.

Let me know if you need anything.
aloha
calvin