Car Spec: 97 Civic DX Coupe with a 94 GS-R swap; Bone stock (obd2 to obd1 conversion) [the car was a hand-me down by my brother in law. So i know the car was taken care of]

I am having an issue with my radiator steaming. Roughly after 7-10 minutes of turning on the car on, my radiator starts to steam up. Not massive steam, but like how the exhaust steams out on a cold day before reaching operating temps.

I have done numerous coolant flushes and bleed of the system. I have changed the thermostat, cooling fan switch on the T-Stat housing, Coolant temp switch/sensor (one for the gauge, and one for the ecu/ecm). My radiator fan will not kick on. I tested the fan straight to the battery, jumping the connection at the T-Stat housing and the relay. They all checked out great. The engine isnt overheating (according to the temp gauge. The water pump isnt leaking any coolant, bone dry. The HG was changed before I got the car, and isnt leaking coolant or oil.

Just a note: I recieved the car in late 2016 and only put 75 miles on since Feb. of 2017. Checked under the oil cap and there is a slight milky residue under the oil cap. The oil is fine.

Any idea what might be causing this?

 

tried a compression test?
if that checks out i'd pressure test the rad.
the local vato zone or the like will rent you the special tools free with deposit.

 

Sorry major NOOB here, but is there a difference in doing compression vs rad test? Planning on doing it tomorrow.

 

YouTube the different if you don't know. Not hard at all.

 

 

Radiator core or welds may have a small leak. Radiator cap losing pressure? Any coolant loss?

 

No coolant loss. I didn't pressure test my old Rad. but got a working one from my brother in law, and yet same symptoms still showed up. I did a block test, and it was okay. The fluid show no changes in color. Im assuming its probably an electrical issue.

 

could be as simple as a bad radiator cap...ive been there before smh

 

so the fan never comes on? I would check the engine temp from outside the car with a handheld temp meter... anytime i have had a fan fail my cars will over heat ..your gauge may not be working correctly, then go from there ..if its steaming more then likely there is a small leak somewhere

 

That could be the cause of the overheating. It may not seem like a big deal at first, but your Honda must have a working radiator fan. Without it, you will overheat, which could easily lead to a warped head, or blown head gasket.

See this:


That's a red flag. If the previous owner didn't address the cause of the blown head gasket (probably non-functional radiator fan), you could be in for the same thing soon.

The oil seems far from fine. Drain some from the oil pan plug into a shallow jar lid. Look for milkiness there as well.

I would proceed on the following hypothesis. The previous owner either didn't notice or didn't care that the radiator fan didn't work. The engine overheated, causing a blown head gasket. Previous owner replaced the head gasket. This may have continued through one or two cycles. You now have the car, and its head gasket may be blown. If you don't get the radiator fan working, it's going to happen again.

You can save yourself a lot of trouble by doing a leak down test, which will test the integrity of the head gasket. OTOH, whether the HG is good or bad, I'd be suspicious of any car that had a new HG but non-operating coolant fan. It says the mechanic didn't know what they were doing. The head may not have been resurfaced, which means another blown head gasket is in your future. If it were my car, I'd resurface the head and replace the gasket, diagnose the coolant fan issue, then fix what's needed to get it working again.