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Bought a new car - '98 TDI - and I have a couple Qs

2435 Views 11 Replies 3 Participants Last post by  soncasey
I crashed my '97 TD and bought a '98 (1.9L L4 FI) TDI with a few problems.

1. The temperature gauge won't move past the 1/4 mark. -Thermostat? I can't find a write-up for it. Is it difficult?

2. It wouldn't start this morning (-10C (~14F)). Can I take the block heater from my '97 and install it on the '98?

3. I don't know if this is related, but the check engine light is on. Could it be an indicator for a glow plug being out?

4. There's a hole in a small hose (I have NO idea what it is called or where it goes/comes from - centre-right of engine on the top going into a wide rubber tube (sorry)) and I get intermittent boost and I can hear blast of air while I'm driving. It also puffs black smoke if I hit the gas pedal.

There should be more problems to ask about, it's our first day together.

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For my second question I found the write-up for the coolant heater. Is there no option for a direct transfer for block heater on my '97 to the '98 TDI?
The coolant heater should be direct remove-replace on the other car. The CEL is probably the ecu hose. There's a writeup in the FAQ. I'll bet the small hose is coming from the CCV (hockey puck)? It has to be connected. I think the thermostat is below the water pump.
1. Sounds like the thermostat or a bad sensor. I could fix it at the same time you move your coolant heater over. It's in the flange near the oil cooler, under the injection pump. It's a pain to get to and be careful when removing the hoses to not crack the plastic parts.

3. First thing to check is the ECU hose: http://myturbodiesel.com/1000q_how_to/a3b4/ecuhosechip.htm the reason it's the first writeup at the top is because it happens to every 96-99 mk3 TDI.

4. It has to be the CCV because it's the only hose on the top center right that goes into a wide rubber tube. Fix the hole, do a visual inspection of all the holes, especially the rubber elbow right before the intake manifold (tends to dry out and crack because it's close to the EGR hoses) all holes and do a boost leak test. http://www.myturbodiesel.com/1000q_how_to/multi/boostleaks.htm

If you do a code scan you'll probably find the code for a bad ecu. This is the hose.
And can I transfer my old block heater from the 97 over to the 98 TDI from the back of the block?
I thought it was a frostheater. From your description, it's a freeze plug heater that requires you to punch out a freeze plug to insert it.

I'm not sure the part number so I don't know. Since you'll probably be working on the thermostat, the frostheater goes in the same area.
I might have to try that Frostheater if this block heater won't come out. Is there a method to remove it from the block? I've followed the cord to the back (deep-back and very messy!) but I can't seem to wriggle it out.
Is there a pattern or colour code for vacuum lines?
I've read somewhere that I will need:
3 ft red and blue 3mm Inside Diameter firm silicone
12 ft black 3mm ID firm silicone
5 ft black 4mm ID soft silicone
If they aren't coordinated already, where should I run each?

I'm planning on changing the thermostat from underneath, is this recommended? Is a "Stant" thermostat reliable?

I found some info on the hoses on tdiclub. Hope that helps someone else aswell.

This thermostat is a real POS. The housing came off nicely but the coolant hose made a horrible mess and when I had that under control I yanked out the thermostat and it blasted coolant all over the damn place! Anyhow, I can't find any way to put the thermostat back in with the gasket on the new housing without it rolling up or popping loose.
Any ideas?

The check engine light was an internal control memory module. I'm not sure of any codes or anything. I was told I need a new computer.
Yes, internal control memory module is 99% the ecu hose, the link was posted earlier. If this is the problem you don't need a new ECU.

While you're not supposed to use gasket maker on the gasket, maybe a tiny smear will hold it in place and act like glue? You're talking about the paper gasket right? If you're talking about an o-ring, just make sure it's not pinched or twisted.
I will try to get at that ECU if I can get those quarter-turn fasteners off tomorrow, if I can solve this thermostat. I know the small black hose going into the intake had a hole at the intake (so did the intake itself), but I will inspect tomorrow. The rubber O-ring is not really seating properly and it jiggles around when I try to tilt it into the hole. Would a tiny dab of super glue be bad for it? Or will it seat itself once I tighten it up?
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