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'93 Toyota Pick-Up (4 cyl.) problems

Hi,

I have a 1993 standard 4WD Toyota pick up (4 cyl.) and I've been having problems with it this year.

Back in April of 04, I noticed that after the truck warmed up, the engine would rev and then slow, when idling, by itself. I assumed it was in need of a tune up.

Then, during the summer, the truck overheated (since the antifreeze was gone, without an "apparent" leak). So, I ran water in the radiator, to try and find a leak, which I did not. I would have to add water every 2 weeks or so. Then when cold weather came, I replaced the water with the proper antifreeze/water mixture, having to add some, every 2 or three weeks.

Then I brought the truck to Toyota, for a "tune up", since the "revving issue" was still ongoing. They told me that the engine was not in need of a tune up, but that the radiator and thermostat needed to be replaced. I didn't understand how being low on antifreeze would cause a revving issue, they agreed that there was no leak, but insisted that replacing the radiator & thermostat would fix the problem, so I reluctantly agreed.

Now, (out $400), I still have the same problem, slow loss of antifreeze and "revving". I called Toyota and they said it could be the head gasket. However, it has no other symptoms of a head gasket (ie. no loss of power, no oil in the antifreeze or vice versa)

When I stop the truck and turn off the engine, I can usually hear some radiator fluid being dumped into the reservior. They say it's not supposed to do that. Also, now, since the radiator was replaced, when I check the fluid, I open the radiator cap and it sucks air in and dumps fluid in the reservior, so it's hard to tell how much fluid is being lost.

Toyota said that they will diagnose it at no cost, but I am afraid they will recommend another expensive (& possibly unneccessary) repair, to "see" if that fixes it.

Anyone have any suggestions?

Thanks!

N.

Reply to
spamalicious
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Sounds like a coolant leak into one (or more) of the cylinders. It may not be the head gasket per se; it's possible the aluminum head has corroded around one of the water ports allowing it to bridge into the cylinder head dome. This is not uncommon on older engines. Fortunately, it can usually be repaired by a good machine shop: they grind out the corroded area, fill it back in by aluminum welding, and then re-surface the head.

Regards, Michael

Reply to
DeepDiver

Thanks, Michael! It sounds labor-intensive - does this type of repair cost $$$?

N.

Reply to
spamalicious

As far as the corrosion repair, no. Of course it depends on the extent of the damage, the skill of your machine shop, and their rates. But, if I remember correctly, it was only about $40 to weld mine up. Of course, that's in addition to the head re-surfacing and any other machine work that may be needed (e.g., valve guides replaced, valve seats ground and lapped, etc.). And then you have to factor in the cost of the head R&R and any parts (not too expensive if you DIY, fairly expensive if you pay a shop to do the job).

Regards, Michael

Reply to
DeepDiver

The problem with these electronic controlled engines is that the only way the control unit knows what temp the engine is is to look at the temp sensor if the cooling system is not warming up it can only treat the engine as cold fast idle richer mixtures ect. sounds like they treated the first symptom and then the underlying fault surfaced due to the now increased temp and pressure in the cooling system I cant comment on the price paid but they wouldn't have known about the head problem at the time. Joe

Reply to
Joe

Joe is right on- also have the dealer really look for a small leak. They may have to do the presure test on the system while the engine is warm to see the trouble. Some jr. mechs only check when cold which is the obvious method. Sometimes a problem will only show when warm due to expansion. My fiancee Xterra was losing coolant at a similar rate ( no revs but ) I found a very small pinhole leak on a heater hose that only leaked while running, wiht heater off, when warmed up! This fixed the trouble. Reving could be anything, 02 sensor, MAP sensor, TPS etc etc.. The coolant issue could have caused it too. A good mechanic would test drive and keep working- find a good local private shop that specializes in Toy. They see older trucks/cars more than the dealer and know how to deal with older vehicle specific trouble. Not a bag on dealers- people who buy used are usally short of cash and thus cannot afford the dealer, so they don't get the opp to work on these older gems.

Reply to
cstem

I gotta say, when I read your car's symptoms, I thought you were describing my '89 4x4 4cylinder truck. My truck's been behaving exactly like yours. Like you, I took mine to Toyota, and discussed it with a tech I know there. Another tech came over, and we scratched our heads and spit, and we all agreed it was likely my truck needs a new head gasket--at least. And we all agreed "who knows what you might find once you get her opened up". They wanted 2 grand for the job. I said if I was going to invest that kind of money in my truck, it would be my NEW truck. So I went out and got the '05

4x4 regular cab Tacoma. Love it.

If I had more ambition (and wasn't driving a new truck) I'd do the rebuild myself, in the garage. Although it's right on the edge of my DIY skills. Anyway, your head gasket is likely going, and it is something you can DIY. Plus, if you get stuck, this board seems like the perfect venue for good advice.

Good luck, Bruce

PS--Anybody want to buy an '89 with a bad head gasket?

Reply to
Anglerboy

Well after all that worry, the truck was fixed for a minimal cost ($40!). Toyota had the truck yesterday a.m., so they could verify the revving issue.

They did a compression check and verified that there was NOT a head gasket leak. (whew!) Then they did a pressure test (again) and found a "good leak", due to rusted clamps, where the hoses connect to a valve at the firewall in front of the heater core. Obviously, they didn't do the pressure test right (or complete) the first time (as cstem suggested).

The funny thing was, that when I picked up the truck, I drove 5 mins, stopped at a stoplight and it started "revving" again. But then after a few more mins, it stopped. (Maybe the control unit didn't get the message that the problem was fixed.) Anyway, it ran fine the rest of the way home and it was ok this morning, no smell of antifreeze and no dumping of fluid to the reservoir after stopping.

Thanks to those who responded.

Eric

Reply to
spamalicious

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