1992 D21 KA24e Low Compression on #2 & #3

Post by **Burtman** » Mon May 17, 2021 8:51 am

First of all, thanks to all for this wonderful forum. Although this is only me second post, it is hard to count how many times I have used this forum to diagnose and fix/repair numerous problems and challenges with my D21 truck. But I am now faced with a project where I need some guidance/advice beyond what I am able to find anywhere online. Any advice, counsel or suggestions others may offer is much welcome and very appreciated.

I have a 1992 Nissan D21 with a KA24e engine with ~ 142K miles.

Current Symptoms:

Low compression on #2 & #3 cylinders (~ 30+ psi).
Compression is fine on #1 & #4 cylinders (~165 psi).
No difference in compression between wet & dry compression tests (indicating “problem” is on upper/valve side of pistons).
I am pretty sure low compression is driven by open/damaged exhaust valves as you can “hear” it through exhaust when under load
Rough idle and low power (of course)

Questions:

From what I understand, I am now faced with replacing the hydraulic lifters and possibly valves as well…How likely is the issue with ONLY the hydraulic lifters and not the valves?
Should I plan on replacing both (lifters and valves)? If the valves are also replaced, will it require any machining on the head?
Anything else I should do or check? Suggestions or advice?
Are there any specific posts or videos I should reference that will help me to attempt such a project?
Is it worth it? Any idea of costs?

I am fairly experienced with working on engines, but this would be the first time I have ever replaced lifters or removed a head and attempted any valve work. I am more than willing to give it a shot (and see it as an interesting project), but I’d like to get a bit more advice/counsel before I take it on (a man has got to know his imitations)

Background:
Prior to my current situation, I experienced a very loud “knocking” which I assumed were some sticky lifters. I used Marvel mystery oil and the knocking eventually subsided, so I assumed I had a sticky lifter (or 2) which was corrected with the oil treatment.

I have replaced timing chain, guides, seals, etc. as well as the harmonic balancer/pulley (because I damaged the original one during removal) at ~107K miles. The chain guide later "came loose " (I heard the rattle) so I had to re-install it again at ~133K when I noticed the cam had jumped a tooth. I am thinking this might even be part of the root cause of my current problems? Who knows...

The truck belonged to my pop who passed away ~16 years ago, so there are some sentimental strings attached to keeping it running as long as possible. It is nice to have around for home projects and to haul stuff, but it isn’t a critical vehicle so I can take my time and work on it without having to rush. On the other hand, I want to be reasonable about what it will take (in both time and $s) to keep the truck running. If it is time to let the truck go, then I can do that (albeit reluctantly).

Sorry for the long post...and thanks again in advance for any help or advice.

Post by **VStar650CL** » Mon May 17, 2021 10:17 am

My guess is you have a head gasket that's blown between 2~3. Worn lifters or cam can cause a miss but not low compression, the valves would be staying shut and not open. Two valves with holes in adjacent cylinders is very unlikely, so what's left is the gasket or a cracked head. Not all cylinder-to-cylinder head gasket failures cross the cooling jacket, and when they don't, the symptoms are exactly what you have.

Post by **Burtman** » Mon May 17, 2021 6:27 pm

Thanks Vstar...makes a lot of sense. So am I correct to assume that that I can remove the head without completely disassembling all the lifters, valves, etc.? And assuming it is just the head gasket, I would think replacing it would not be such a great challenge. But if the head turns out to be cracked, I am guessing it is probably time to say good bye to the "gray beast" (which is what my kids call the truck)?

Any "might as well" items you recommend I should take care of if I decide to go for it? Any "gotcha's" I need to look out for? I have an FSM, so I will be sure to check it out thoroughly before taking the project on. Any videos or posts I should look for?

Thanks again bud...I am starting to feel some hope again.

Post by **VStar650CL** » Mon May 17, 2021 6:52 pm

The stuff that needs to come off for the head gasket is mostly under the timing cover, so new timing components (chains, guides, tensioner) are obviously a good idea. Been a long time since I've been inside a KA, but I recall the tension-side guides were problematic enough to warrant a bulletin before Nissan changed the design. I don't recall if it ran through '92 (the KA oldtimers in here will know better than I do), but the point is, you might as well replace whatever is in there.

Post by **AZhitman** » Mon May 17, 2021 7:26 pm

Yes, the TC guides need to be updated. That was an issue throughout the run.

If I were pulling the head, I'd go the extra few hours and re-ring it, replace freeze plugs, F/R main seals, and hoses. Basically, you'll have a brand new engine.

Post by **Burtman** » Mon May 17, 2021 7:42 pm

Thanks guys. But I noted in my original post that I have already replaced the timing chain, guides, seals etc. @ 107K miles. I'll check them out to make sure everything looks OK, but I don't plan to replace them again unless something obvious requires it.

Post by **AZhitman** » Mon May 17, 2021 7:49 pm

Whoops. My bad, B. Didn't read thoroughly!

Post by **VStar650CL** » Mon May 17, 2021 8:18 pm

AZhitman wrote: ↑
Mon May 17, 2021 7:49 pm
Whoops. My bad, B. Didn't read thoroughly!

Second that. Soooooorry!

Post by **Burtman** » Fri Jun 04, 2021 7:47 pm

I got the head off today (yeah...I'm taking my time). I was hopeful VStar was correct, but I have to admit I was a bit skeptical. Sonofagun...VStar was spot-on. Definitive head-gasket failure between cylinders 2 & 3. I'll try to post a pic if I can (not sure how). VStar...you are da man! I am humbled by your ability to peg the problem based only on my description of symptoms. Wow...

Post by **Burtman** » Fri Jun 04, 2021 7:57 pm

Engine block Pic

Post by **Burtman** » Fri Jun 04, 2021 7:58 pm

Underside of head - valve pics

Post by **Burtman** » Fri Jun 04, 2021 8:03 pm

Plan now is to buy/replace the following:

Head gasket (of course)
New Head bolts
Intake & Exhaust manifold gaskets
New thermostat / gasket
New hoses - coolant, bypass, fuel, etc.
Rocker arms and lifters (kit?)

Anything else I should consider? What would you do if you were me?

Should I have head machined prior to reinstall? Is this necessary? Might be a challenge to find someone to do this, and if I do, how much should this cost?

Do valves (see pic above) look OK?

Any tips, suggestions, or advice is much appreciated. Thanks Guys!

Post by **VStar650CL** » Sat Jun 05, 2021 3:10 am

Those valves look fine, so given the good compression on 1 and 4 you can probably leave them alone. Check the head with a straight-edge, if it isn't warped then leave the deck alone too. Dunno how prone the KA24's are to worn valve seals, but you might want to consider that. AZ and some of the other oldtimers here can probably advise you better about that than I can.

Post by **Burtman** » Sat Jun 05, 2021 8:15 am

Thanks again VStar. I appreciate you very much.

Post by **Burtman** » Sat Jun 05, 2021 8:25 am

Another Question...I was considering replacing all my rocker arms/lifters based on what I have read elsewhere. I have experienced the annoying lifter "tick" off and on in the past with it getting quite loud at times. I ran some Lucas, ATF, etc. which helped quiet down the noise a lot, but it still exists from time to time. After looking at the price for new rocker arms (~$55 each), I see that a total replacement could get really expensive. Is total replacement of rocker arms/lifters really necessary? Is it worth it? Can I just remove and clean the arms/lifters rather than replace? Maybe replace some but not all? How would I know which ones need replacement?

Thoughts? Suggestions? Advice? What would you do if you were me?

Post by **VStar650CL** » Sat Jun 05, 2021 8:27 am

Burtman wrote: ↑
Sat Jun 05, 2021 8:15 am
Thanks again VStar. I appreciate you very much.

You're most welcome, glad to help. Once she's back together, happy motoring!

Post by **Burtman** » Sat Jun 05, 2021 8:30 am

What is this????

I found 2 of these spacers (see pic??) loose (one of the ground under the engine and one on the engine block) after removing the head. Any idea of what these might be? I hate it when this happens...UGH.

Post by **VStar650CL** » Sat Jun 05, 2021 8:31 am

Burtman wrote: ↑
Sat Jun 05, 2021 8:25 am
Another Question...I was considering replacing all my rocker arms/lifters based on what I have read elsewhere. I have experienced the annoying lifter "tick" off and on in the past with it getting quite loud at times. I ran some Lucas, ATF, etc. which helped quiet down the noise a lot, but it still exists from time to time. After looking at the price for new rocker arms (~$55 each), I see that a total replacement could get really expensive. Is total replacement of rocker arms/lifters really necessary? Is it worth it? Can I just remove and clean the arms/lifters rather than replace? Maybe replace some but not all? How would I know which ones need replacement?

Ticky lifters generally aren't hurting anything besides your ears. Unless there are other issues like camshaft wear, I'd leave it alone.

Post by **VStar650CL** » Sat Jun 05, 2021 8:40 am

Burtman wrote: ↑
Sat Jun 05, 2021 8:30 am
I found 2 of these spacers (see pic??) loose (one of the ground under the engine and one on the engine block) after removing the head. Any idea of what these might be? I hate it when this happens...UGH.

I don't think they're spacers, they look like the alignment pins that go in the holes at the corners of the head to keep the gasket and head lined up with the block. Look at the pics you posted of the head, you'll notice 4 of the bolt holes are counter-bored. If you left out one of them I'd say it's not a problem, but 3 out of 4 could let the gasket or head shift position and cause that new gasket to fail. Better pull it back out.

Post by **Burtman** » Sun Jun 06, 2021 7:10 am

Awesome! Thanks again VStar! I’d like to say that I would’ve figured that out eventually. Even if so, you saved me the time and frustration of doing so.

Plan is to get the parts and put this thing back together in the next few days. I’ll keep you posted.

Lol...I’m still pretty freaking amazed how you so accurately pegged the precise point of the head gasket leak based on my vague symptoms description. I was beginning to wonder if the “gray beast” was finally at EOL. The current prospect of getting her running again (and likely better than before) for under $200 in parts is like manna from heaven.

Post by **VStar650CL** » Sun Jun 06, 2021 9:25 am

Burtman wrote: ↑
Sun Jun 06, 2021 7:10 am
Lol...I’m still pretty freaking amazed how you so accurately pegged the precise point of the head gasket leak based on my vague symptoms description.

It wasn't complicated. Lots of I-4 riceburners have sleeves that are so close together that they don't cross the cooling jacket, and anything that close can also permit blow-throughs. The clue was the adjacent cylinders, that immediately smacks of head gasket whether there's coolant involved or not. Anyway, you're most welcome, happy to help.

Post by **Burtman** » Mon Jun 07, 2021 6:19 am

I'm ordering part for head gasket replacement. Below is the parts list...thought I'd take care of a few other things while I was at it. Thought I'd throw it out there for any feedback or suggestions which are welcome and appreciated
- Anything I am replacing which is not really necessary? (Save $s?)
- Anything I missed?
- I am ordering from nissanpartsdeal.com - - Is there a better place to buy Parts?

Thanks in advance!

Post by **VStar650CL** » Mon Jun 07, 2021 6:49 am

Tube seals, I don't think they're included with the VC gasket.

Post by **Burtman** » Mon Jun 07, 2021 7:41 am

Tube seals?? Sorry man...I don't know what that is? I even did a search and could not figure it out. If you mean the "plugs" that seal the ends of the rocker cover, they are on my list.

Post by **VStar650CL** » Mon Jun 07, 2021 8:25 am

The tubes where the coils go in. Aftermarket VC sets usually include them, but I think Nissan sells the perimeter gasket and tube seals as separate parts.

Post by **Burtman** » Mon Jun 07, 2021 9:14 am

I’m sorry, but I am stumped. I have no idea what a “tube seal” is for this engine. Maybe someone could send me a pic or part number?

Post by **Burtman** » Mon Jun 07, 2021 9:15 am

I’m sorry, but I am stumped. I have no idea what a “tube seal” is for this engine. Maybe someone could send me a pic or part number?

Post by **VStar650CL** » Mon Jun 07, 2021 11:04 am

Never mind, I just realized yours is too early for COP coils. No tubes and no seals, my bad.

1992 D21 KA24e Low Compression on #2 & #3

1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

Re: 1992 D21 KA24e Low Compression on #2 & #3

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