tfan

Got the 88 4runner with a 22re from my dad - bought new in 88 been a daily driver all this time.....but not maintained all to well over the last few years. I just replaced both timing chain and headgasket. re torqued everything and checked the chain had not gone all the way through the timing cover "yet"...... No history of major overheat. Just normal abuse and an issue with coolant disappearing slowly with no signs of leakage and an obviously broken chain guide

I noticed the nasty brown chocolate milk coolant I took out and was fairly certain the headgasket had started to leak even though the compression checked out and a leak down test showed every thing was in spec and still does!
Everything seemed fine going back together...... I've been checking to see the temp is ok and fluids are as they should be - have gone less than 50 miles and now the coolant is like bublegum. Arrgh! Oil is fine --------- Am getting a bit more than puzzled.....any help out there? warped head possibly? Messed a gasket up or missed something ......suggestions? thnkz

sam333

Blown head gasket or cracked head. Slowly disappearing coolant, I would have the head pressure tested for cracks when you pull it. Also check the head and deck for warping. Do it all or you might be pulling it apart again.


When you removed the head gasket the first time, could you see a spot where it was leaking?If it was an old leak in the head gasket its usually easy to see.

tfan

Ok well I'm already pulling it apart again - so hoping the second time is a charm and the old family wagon will be resurrected for the grand kid ....this started with a 71 corolla then a 75 Hi-lux - the truck is still tickin along....the corolla got squished, the corona went away, and the camry will get passed on to one of the grand daughters......
When the head was off the first time there was some evidence that the oil galley in the center was pushing into one of the coolant ports but it was not really apparent. I also saw some evedence at the back corner on the passenger side of possible gasket issues..... the timing chain has deffinately left its marks too but I looked closly and could not discern any pin holes or cracks. I don't have a truing slab so I guess Ill have to take the head to a friend to see if it is warped.....

sam333

If you take the head to a machine shop to have it pressure tested they can check to see if its warped, but the block you will have to do in the car . You can buy a machinists straight edge for about $50 ( dont use a ruller) and check both yourself. If the cracks in the head are small you will never see them. If the head or block is warped, then you will need to resurface them or your head gasket will blow again.

tfan

Thanks Sam,

Been in the machine shop before running the milling machines, lathes, CNC muli-axis muli-tool mills and other big tools using CADCAM in a previous life. I've got the straight edge and feely gauges but since I've known this engine since it was "show room new" I skipped that check. bad on me!! I'll check it but if its warped enough to tell with a straight edge I'm sure that the next thing to do is bolt it into the bridgeport and true it up, so off to the machine shop! But what about replacing the head? this beast has 220K on it and a valve job might be a good thing to do. it would eliminate the possible cracks in the head passages as well as eliminating possible warpage..... expensive though! a pass with the flycutter is free. well almost.....

sam333

I would have it pressure checked first( they always stop there if there is a problem anyway) and if ok, then do a valve job. If you buy a reman you will still get a high mile head. If you get a valve job quote from most machine shops, it usually includes cleaning, pressure testing, checking for warps ,valves/seats, but usually not the valve adjustment( which can be expensive if you have shims or buckets). I usually comparison shop, but if you have the work done at a good shop, at least you will know what was done( labor/parts). Unlike some of the cheap engine rebuild mills which can turn out some real junk.

If you have the money to go new though, go for it.

It must be nice to have the tools.

tfan

Razed,
The stuff in the radiator after about ten miles is bubblegum and the dipstick tells me the oil level went down noticeably..... So the most obvious leak is via the high pressure side of the valve train oil galleys. Head is now off again and I inspected for warpage..... not noticeable in any direction. The kid is headed to the junk yard tomorrow to see if there is any likely doner. I've priced NOS from several places on the coast as well as the referbs.... I think the NOS is likely the best bet if I get what is actually advertised. Any body with experience getting parts from sellers on E-Bay let me know.

tfan

Sam,
I will be sending the head to get pressure checked before I shell out the $$ for new. If the kid finds something that is still buttoned up and can be extracted intact at the yard we may end up with an inexpensive fix..I rather doubt it though.... more likely I get to wait till the brown truck shows up, either way I'm almost positive the head has something bad goin on. By the way, the leak at the headgasket seems to have been around the center bolt driver side but did not look like an old issue getting worse. I have a feeling that I may not have the whole story about overheating. My dad may not have noticed... IYKWIM.....

tfan

Ok follow up - see album - really bad timing cover finally crapped out - never found the leak in the head suspected a crack in the water jacket on #1 near the oil inlet at front - replaced head and timing cover - learned several very important lessons. The head is by far, more easy to replace with new or rebuilt than to build up from parts, and it's not worth the disassembly time and cost for a pressure test on the suspect head if it costs more than about 50 bucks for the test when a rebuilt head complete can be had for under 300! Oh USE OEM HEAD GASKETS!!! AM head gaskets are crap!

wyoming9

iTrader: (1)

It is pretty much a given if you do the upper end valve job or a higher mileage 22R series engine.

With out doing new lower engine bearings it is only a matter of time to something starts knocking .

Kinda the next weakest link in the chain thing.

tfan

Wyoming,

I've run a 20R up to 353.000+ with out unbuttoning the bottom end, the Corolla and the corona both had way over what my dads 4Runner has at just over 200K, so yes it's possible rod bearings will go, but the knock is definitely detonation, not bottom rod bearings or piston slap. The issues with TPS positioning and knock sensor combined with the rotten regular gas we have is the issue. replacing the TPS fixed the error on the ECU and allowed the timing to be set properly, that's just a part of the adjustments needed to work out bugs caused by major new part installation on a less than meticulously maintained older engine....I'll be running through the settings and bumping the octane to see where the sweet spot is later today.....

tfan

Razed,
Yes the flush and fill has been done 5 times to insure we got the fluids in their respective places and none where it does not belong. Ran oil+filter as well as coolant just to be sure..... both are nice and clean with no evidence of contamination now. Thanks!!