LT5 noise when not running
04-23-2018, 12:09 PM
#1
2nd Gear
Thread Starter
LT5 noise when not running
I have a 1990 ZR1 with 12,000 miles. Recently, after the battery went low, the car started making ticking and pumping sounds. I thought it might be the anti-theft system and thought the problem solved after replacing the battery. However, after 1 week of not running the car, it started making the noise again this weekend. Sounds like it is coming from the oil cooler. Any ideas?
04-23-2018, 01:38 PM
#2
Race Director
Member Since: Feb 2002
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Welcome and grats on your ZR-1
With just the key on you may be hearing the vacuum pump cycling.
Do search here the best site for all ZR-1 related information.
http://www.zr1.net/forum/index.php
http://www.zr1.net/forum/showthread....=vacuum+system
With just the key on you may be hearing the vacuum pump cycling.
Do search here the best site for all ZR-1 related information.
http://www.zr1.net/forum/index.php
http://www.zr1.net/forum/showthread....=vacuum+system
Last edited by FASTAZU; 04-23-2018 at 02:01 PM.
04-26-2018, 11:07 AM
#5
Le Mans Master
Member Since: Oct 2004
Location: South-central Missouri
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After sitting, when the key is turned ON, but the starter hasn't been switched on, there will be a humming coming from the fuel pumps which will quiet soon as the fuel rail is up to pressure.
And, the vacuum pump, located in the passenger side headlight well will run for a few seconds (normally) until vacuum is established before quitting*.
*The pump will come on as needed to maintain minimum vacuum. With NO LEAKS, the pump would not come on again. However, there are many connections and some leaking is almost "a given". However, if the pump does not cycle more than every 10 seconds (engine not running), the system is in need of service, but the secondaries are primed and will still operate normally.
If you determine there is a loss of vacuum causing the pump to run too much (ignition switch ON, but engine not running), let us know and there are procedures for isolating and repairing the leak(s).
If you determine there is a loss of vacuum causing the pump to run too much (ignition switch ON, but engine not running), let us know and there are procedures for isolating and repairing the leak(s).
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jdyoub@tx.rr.com (05-31-2018)
05-31-2018, 12:30 PM
#6
2nd Gear
Thread Starter
I appreciate the feedback. I am having the oil cooler hoses replaced today. Hopefully I don't have any vacuum leaks. The car only has 12K miles, but it is 28 years old. Kind regards,