Overheating trouble!

[Daytona VNT]

Ok, A friend of mine gave me this thing (1990 Daytona VNT) for free and gas is expensive, so I am going to try and fix it up a little. I've got a list of problems so, bare with me. First of all I'm having overheating issues. I have already checked the fan,the thermostat,the water pump and I have even flushed out the cooling system and its still a no go. It only overheats whe driving or under boost. You can run it a 4000 rpms all day long and it won't get hot, just as long as you aren't driving it or applying boost, Do I have a cracked head or blown head gasket(there was no oil in my water or water in my oil and I didn't have any type of smoke coming from my exhaust). Next I have an issue with the lifters/valves. They clatter like hell when under any boost, but without they stay very quiet. Big no. 3, does anyone know how to replace the starter on these things, Its kind of cramped and I can't tell how you would get it in or out. Finally, I have an issue with the throttle. When reving the vehicle in a stopped position/neutral, the engine will cut out at around 2000-3800 rpms (feels like a rev limiter when this happens), once it gets above or below these rpms It doesn't have a problem. The vehicle does have a TPS code so, that may be the answer. Any ideas? Sorry for the long post, but I am new to the whole turbo, non V8 vehicles! Thanks in advance!

[Whorse]

what are your boost levels at when all this is happening? Try running some 94 octane gas and a gallon of methyl hydrate through the system, spray some carb cleaner through the intake and revv it a bit, and go from there. I found on my VNT that changing the plugs and wires, sealing up all vacuum leaks, and cleaning out my intake system as much as possible helped a lot with some of my problems. If you're having a TPS code I'd look at that as well.

[Daytona VNT]

Ok, when watching the stock boost guage, the valves start clattering at about 6 psi and get much worse as the boost increases. I've done the carb cleaner stuff and ran sea-foam in my fuel also, no change. I checked for vacuum leaks and didn't find any. The only thing that you mentioned that I haven't done yet, is change the cap,rotor,plugs,and wires. Do you have any Idea about what may be causing the overheating or how to get a new starter on this thing?

[Will Martin]

Let's see if I can help you here.

Why do you need to replace the starter? Well if the obvious answer is it's defective or not working, there are two ways I do it (depending the space in the hood I'm working in). Take off the intercooler pipes and airbox and you should be able to get at the two screws holding it in the trans housing. Or jack up the car and see if you can work your way in there from the bottom. Which ever works best for you.

If the valves are clattering then it sounds like you may just need to throw a fresh head on there. How many miles are on this beast?

You need to change out your TPS, that one is obvious from what you posted.

The overheating issue.....well, could be a number of things.
-Have you checked or replaced the coolant? It could just need a good flush and some fresh coolant (remember to use at least a good 50/50 mixture).
-Your waterpump could be on it's way out.
-Sticky thermostat.
-Your timing is too advanced.
-You have a head gasket on it's way out. Do a compression test.
-You have a cracked head. Now this is the one that stumped me way back when I was a rookie. lol I had an '89 CSX and it ran fine, but once it warmed up a bit, it would start to overheat and burn coolant. Also, boost would come on kinda late, which we all know VNT's are not supposed to do that. So what I did was clean as much as I could of the head with some superclean and run the car. Right as it was starting to overheat I pulled over and checked the head. Sure enough, the #2 spark plug hole had a tiny hairline crack in it. It would expand as the car got hotter but after it cooled off it would look like nothing was wrong with it.

Either way you got a smoking deal and I'd just through it and freshen it up a bit. Get yourself a good $50 head on here, and MP head bolts and gasket, and see how it goes.

[Daytona VNT]

Will, I've seen what these things sell for if they are in decent shape and now that I have searched around this site, I have realized the potential that these things have. I didn't know these little cars would run like this, so I am in total agreement with you about getting a hell of a deal . Well, thanks for the info Will, and you also Whorse . I forgot to mention that my car is running very rich, not to the point of black smoke, but enough to burn your eyes and nose. I'm thinking that the richness may be contributing to my clattering valves. I'm still not sure about the overheating though. Will, I have done a radiator flush and am running straight coolant. I even removed the thermostat to see if it had any effect. If my timing were advanced too much, wouldn't the car idle like crap, sound like its under a strain, or backfire/missfire occasionally? I will try and get a compression test done, if it checks out ok, this should rule out the gasket or crack, Right? The head looks fairly new even though the car has 120,000 miles on it. I checked all the spark plugs to see if any were abnormaly colored and they all looked the same so I would think that there isn't any coolant getting into my cylinders. As for the water pump... It works but I may just replace it anyways. The deal with the starter (the cylinoid engages but the starter doesn't spin, I can still crank the vehicle by making contact with a screwdriver though ) , well, its not the problem of unbolting it, it's that I want to know how to snake the thing out, theres to much stuff in the way .

[Will Martin]

Quote:

Originally Posted by Daytona VNT Will, I've seen what these things sell for if they are in decent shape and now that I have searched around this site, I have realized the potential that these things have. I didn't know these little cars would run like this, so I am in total agreement with you about getting a hell of a deal . Well, thanks for the info Will, and you also Whorse . I forgot to mention that my car is running very rich, not to the point of black smoke, but enough to burn your eyes and nose. I'm thinking that the richness may be contributing to my clattering valves. I'm still not sure about the overheating though. Will, I have done a radiator flush and am running straight coolant. I even removed the thermostat to see if it had any effect. If my timing were advanced too much, wouldn't the car idle like crap, sound like its under a strain, or backfire/missfire occasionally? I will try and get a compression test done, if it checks out ok, this should rule out the gasket or crack, Right? The head looks fairly new even though the car has 120,000 miles on it. I checked all the spark plugs to see if any were abnormaly colored and they all looked the same so I would think that there isn't any coolant getting into my cylinders. As for the water pump... It works but I may just replace it anyways. The deal with the starter (the cylinoid engages but the starter doesn't spin, I can still crank the vehicle by making contact with a screwdriver though ) , well, its not the problem of unbolting it, it's that I want to know how to snake the thing out, theres to much stuff in the way .

No problem.

It depends on how far the timing was advanced before it would start to do anything, and it also depends of if it's on a 2.2 or 2.5. Stock, the 2.2's like a bit more timing than the 2.5's and can handle just a wee bit better..... And remember, there's cam timing too. Anyhow....

The starter. Okay, now I see you dilema. Well it's a son-of-a bitc# to get it out of there but once you have it disconnected, you should be able to 'wiggle' it out. You're gonna have some scraped up hands though, but you'll manage. I hope you're a patient man. LOL

The issue with the fuel should be addressed first, IMHO, because if you continue to over flood the engine, you'll be in need of a rebuild quick. Most likely you have leaky injectors, but it could be a busted fuel pressure reg as well. I suggest you check your fuel rail and see what's going on there. Check the o-rings on the injectors and the one under the fuel pressure regulator.

Just a suggestion, flush at least 30% of the coolant back into a bucket and pour it back into the container and add some water. That much coolant isn't good for your engine.

Go ahead and do the compression test to see what you come up with. If the numbers pan out, you should be good to go with the headgasket. Just in case, if it comes down to it, DOUBLE CHECK the head bolts to make sure they're okay. Back in my rookie days, my first car, I took it to a "race shop" and when I got it back, it blew a headgasket in one week!!!!!!!! Checked the bolts and guess what? Five of them were not torqued down all the way, not even close. LOL

So if the engine is sound and you just have minor tuning issues, sounds like you've got yourself a good little car. You'll enjoy the small burst of city driving and the surprised look on peoples faces when you give 'em #ell. But you WILL get the speed bug and start to mod it once you get it running properly.

[PUNKslip]

I have waxed a couple motors, both V-8s, and one thing I noticed is when the motor starts to clatter and raise hell, the heat goes up. I noticed that when motor parts start making noise, the friction is up and so does the heat. Do you have good oil pressure, and good oil. Get rid of all that noise and friction, and recheck your engine temps.

John

[sdac_guy]

If you are hearing valve noise ONLY under boost, is it valve pinging? You MUST use premium gas in the car (as it says on the fuel filler door). If you don't use premium and it is valve ping (pre-detonation) you will be looking at a major engine problem before long (cracked or broken piston).

If you are using premium and still have valve ping under boost, then check the basic ignition timing. To do this you have to remove the air filter box (so you can see the timing window in the trans bellhousing). Unplug the temp sensor (two lead plug on the thermostat housing) so that the engine will run at "basic" timing, and with your timing light, check to make sure it is at no more than 12 degrees BTDC. And you turn the distributor to adjust the timing.

Many times running rich at idle is because of a vacuum leak affecting the MAP sensor reading. When the MAP sensor doesn't see enough vacuum at idle, the computer thinks the engine is under load and it will richen the mix. The VNT's are very sensitive to vacuum problems and have a few more lines that can crack or leak than the normal T2 engine.

Barry

[Will Martin]

Quote:

Originally Posted by sdac_guy If you are hearing valve noise ONLY under boost, is it valve pinging? You MUST use premium gas in the car (as it says on the fuel filler door). If you don't use premium and it is valve ping (pre-detonation) you will be looking at a major engine problem before long (cracked or broken piston)..........Barry

Exactly! He told me he was using 87 Octane and I told him he has to use as a minimum premium octane 91/92. Also advised him to use a bottle of fuel sytem cleaner if it has bad gas in it, and to fill it up with premium. I think when he gets all the initial things settled he'll be boosting in no time.

[Daytona VNT]

Hey everyone, thanks for all of your input!!! Yeah, I was using 87 octane . I have put some 93 octane in it, changed all of the fluids, replaced a broken knock sensor, replaced the TPS, and am in the process of timing it. The clattering quit after replacing the TPS and Knock sensor . Its still overheating (no coolant loss or visible evidence to support a blown gasket or cracked head) but I will figure it out. I will do a compression check, and check to see how off my timing is, Maybe fixing the timing problem (if there is one) will get rid of the overheating. I will also go over all of the vaccum hoses again, just to make sure. Hopefully by the end of next week I will already be needing some new front tires Oh, by the way, do you think it would be better (in the hot Texas climate) if I used a low ash synthetic oil, like Rotella T.

[Dan Culkin]

It's probably a blown head gasket. Fill it up with coolant, leave the cap off the radiator, start the car, and rev it up.

See that "carbonation" looking stuff oozing out of the radiator? That's exhaust getting pushed into the coolant.

[ThreeTurbos]

can almost bank on the fact it needs a new HG. clattering (hopefully not pinging) may be a hint that you need some new lash adjusters. id also source yourself a new 02 sensor if i were you. you can do a slip and tuck for the HG and when you are in there check the lash adj's.

common items to replace if you want it to run well.
and if ya want to hammer the boost id get yourself an air/fuel gauge.

just my 02 sense.
best of luck. thats a nice engine.

[glhs727]

where in Texas are you located?

[Daytona VNT]

I live in La Grange

[Daytona VNT]

I got most of the stuff sorted out. Had it running really good and not overheating but now it started a bad miss on the #1 cylinder, its getting fire to that plug and it smells like fresh gasoline coming out of my exhaust. Did one of my injectors take a crap on me?